I'm writing this post in the hope that I no longer have to write long-winded replies in the comments about this topic. I have no idea why anyone would want to read it, but I just needed to get it off my chest so I could stop thinking about it constantly. Also, disclaimer: I wrote this directed towards a more non-Cardinals-expert audience in case I want to show it to anyone I know in real life, so I'm sorry if it seems a little dumbed-down to some people.
Putting it simply, I believe that the St. Louis Cardinals trading for Juan Soto is, in fact, a worthwhile option and something they should definitely strongly pursue.
I furthermore believe that, despite how massive and unprecedented it seems on the surface, it is in fact very much the sort of move that the current Cardinals front office would do, and is in fact it is a deal the Cardinals alone are remarkably well-suited to make for a number of reasons.
This is a unique opportunity in the history of baseball that the Cardinals have stumbled into, like the baseball equivalent to Franz Ferdinand's car stalling right in front of Gavrilo Princip, pistol in hand. All that's left to do is the obvious thing.
I've seen it suggested that the Cardinals should simply wait until Soto hits free agency. The only way the Cardinals are getting Soto is if they trade for him, either now or in the coming offseasons (if Nationals GM Mike Rizzo doesn't get any offers he likes in the meantime). They are not going to get him on the open free agent market. You know why? Because the Cardinals never get the big fish on the open free agent market; they are always priced out, and for good reason. There always seems to be at least one team short-sighted enough to give the big-ticket free agents of a given offseason way too much money, and the Cardinals, wisely, are not among them. It happened to them with Albert Pujols and David Price, and the Cardinals made the right decision and let those teams waste their money. If it happened for those two guys, great players who hit free agency around 30 years old, then what the heck do you think is gonna happen when Juan freaking Soto at age 25? To suggest that the Cardinals stand anything resembling a chance in that market is lunacy.
The other alternative I have seen is that the Cardinals should spend their time and resources on getting more pitching, particularly starting pitching. Considering the Cardinals have only two big league starters currently pitching for the team, I think we can all agree on that point.
The thing is that the pursuit of starting pitching depth and the pursuit of Juan Soto are not mutually exclusive in the slightest. The Cardinals are not going after one of the top-tier available starter; they are simply not going to do that, nor should they. It is neither something they should pay for nor something they really need.
Why shouldn't they pay for it? The pitching market at the trade deadline is hugely inflated in a way the position player market is not, simply because every contending team could use one more pitcher, whereas the position players serve much more specific suitors. The Yankees' and Dodgers' pitching staffs are both in the top 3 in baseball in ERA and FIP, and yet both fanbases are clamoring for more pitching this deadline, and both teams are clearly in the market. Point being, every team is in on every pitcher, more or less, which is not an advantageous position to be in while negotiating. Also, two of the top starters on the market, Tyler Mahle and Luis Castillo, are within the division, meaning they would probably cost an additional premium to acquire.
Why don't they need it? You shouldn't pay for something you don't really need, especially if you have to pay a premium price. The Cardinals don't really need multiple years of control in the pitcher(s) they acquire this deadline, but most of the top pitchers on the market have multiple years left. The Cardinals' lack of pitching depth in recent years is due to two things: firstly, there was a hole in the pitching depth at the upper levels of the Cardinals system (in large part due to losing picks in the 2017 draft and the Marcell Ozuna trade). This really hit its nadir last season when there was just nobody who could get outs for the team. That hole is closing with every subsequent year, and this year already it isn't quite as bad (Zack Thompson and Andre Pallante are a lot better than anything the 2021 system could drum up). Getting an ace pitcher with multiple years of control does not make sense with the Cardinals' timeline, since in a couple years they'll be blocking and potentially hampering the development of at least one of Michael McGreevy, Tink Hence, Cooper Hjerpe, Gordon Graceffo, or others, as well as blocking the pitchers we already have once they are healthy. Also, premium pitching is simply too rich for the Cardinals' blood, and the team (and the stadium) is built around the concept of mitigating the effects of not paying for it. The Cardinals need some good innings more than they need a lot of great innings, mostly because of truly awful injury luck.
So, the logical choice is to get a rental. This idea seems pretty in line with how the Cardinals' front office thinks. As it happens, rentals, even pretty good ones, tend to be pretty cheap. A Juan Soto trade, by contrast, is going to involve the top prospects in the Cardinals' system. Those deals are likely going to have absolutely no overlap. Last year, they got Wade LeBlanc for nothing, JA Happ for Evan Sisk, and Jon Lester for Lane Thomas. No Soto trade would ever involve Evan Sisk or Lane Thomas, even if they were still in the system. Thus, the Cardinals can, and should, pursue both things at once, even if they're going after slightly better rentals than those.
So, since it looks like the Cardinals can go after Soto, let's look at why they should.
The trade for Juan Soto is going to involve the system's top prospects and young players. It will certainly be some combination of Nolan Gorman, Dylan Carlson, Alec Burleson, Masyn Winn, the aforementioned pitchers, and maybe even Jordan Walker, though recent reports suggest that they're trying to keep him at least. The first reason this trade is fine is because, in all likelihood, none of these players are even going to approach what the Cardinals are getting in return. Which is to say, as much as us fans love our prospects, especially Cardinals fans, they are not going to turn into stars.
Most of the best prospects in baseball are considered the best because they seem guaranteed to be average or slightly above average big leaguers, not because they're going to be stars. For Dylan Carlson, a career like Nick Markakis's career or Kevin Kiermaier's career is probably an above 50th percentile projection for him. That's a good outcome: 2-3 WAR per year for 10 years. He's probably not going to be, nor was he ever going to become a player on par with George Springer or Kyle Tucker. It's the same story with Nolan Gorman, and is also true for any of the rest of our prospects not named Jordan Walker, and even with him it's far from a guarantee. But of course, we can never really be sure what prospects or young players are going to turn into, which is why all trades are inherently risky. However, what makes these players appealing to the Nationals is not that Mike Rizzo is sure they're going to become stars, but that these are sure-fire MLB-ready players with many years of control left.
The Cardinal Way:
The Atlas holding up the proverbial globe of the Cardinals' sustained success is precisely their ability to draft and develop these sorts of players. The Cardinals aren't a good franchise because they're churning out Aaron Judges and Trea Turners; they're consistently good because they've become experts at producing Allen Craigs, Matt Adamses, Jon Jays, Daniel Descalsos, Tommy Edmans, and Brendan Donovans like the organization is some sort of factory. Guys like Albert Pujols, Oscar Taveras, and Jordan Walker only come around every once in a while.
This is all to say that the Cardinals' system is usually flush with more average or at least replacement level talent than they know what to do with. It's their bread and butter. That's precisely why the Cardinals are perfectly positioned to make this trade, because the perfect complement to a deep roster of average to above average talent is a few stars to build around. Trading for Soto fits this need exactly, and, if we accept that what we're giving up will likely be average players, we can be comfortable knowing we'll have new average players to replace them. Also, sometimes the Cardinals' system is a little too good at its job, such as right now. The team has a bit of roster crunch brewing, where they have too many MLB-ready position players at the same time. This has meant that Alec Burleson has had to stay down in AAA, despite proving that he's MLB-ready at this point. Alec Burleson isn't generating any wins for the team while being stuck in AAA. It is to the Cardinals' advantage to trade away some of this depth every once in a while since they can't effectively use it once it reaches critical mass. This is yet another reason this style of trade works so well for the Cardinals and would work well for Soto.
A lot of the team's recent success can be credited to this style of roster construction. Indeed, we have a lot to base this type of trade on because the Cardinals have made three of them in the past five years: namely the Marcell Ozuna trade in 2017, the Paul Goldschmidt trade in 2018, and the Nolan Arenado trade in 2021. They all bear a strong resemblance to a potential Soto trade: trade young MLB talent and prospects for a star player who needs out of their current organization. I think it's valuable to look at a Soto trade through this lens to see the range of possible outcomes.
Let's save the worst of those three for later. With the Goldschmidt trade, the Cardinals sent two young, MLB-ready players in Luke Weaver and Carson Kelly as well as a prospect, Andrew Young, to the D-backs in exchange for one year of Goldschmidt. In the Arenado trade the Cardinals sent one MLB-ready player, Austin Gomber, and four prospects to the Rockies for what was effectively one year of Arenado (from the Rockies perspective, he was going to opt out) and over $50m. Fun fact, the opt out was only in Arenado's contract because the Rockies' GM convinced Nolan to put it in, and that ended up completely destroying any leverage they had and is probably largely responsible for the $50m they had to fork over. Very Rockies move to say the least.
A Soto trade would essentially be like these trades on steroids. There would be a mix of MLB-ready guys and prospects; those guys would just be of a higher caliber since it's for 2.4 years of Soto instead of one year of Goldy or, for negotiating purposes, one year of Arenado, which seems like a completely fair upcharge. I think Cardinals fans would almost universally agree that the Goldy and Arenado deals were great, and if you accept that the Soto trade is essentially an upscaled version, why wouldn't you want that to happen?
Well, as mentioned, trades have risk. There's always a chance of it not working out the way you hope. In comes our third example, the Ozuna trade, which worked out worse in every regard. The Cardinals sent prospects Sandy Alcantara, Zac Gallen, and Daniel Castano as well as young OF Magneuris Sierra to the Marlins. On what they gave up and what they took in, the Cardinals failed abysmally.
First, what they sent out turned into something unimaginably great. The Cardinals really had no control over this; this is what gives trades for prospects their aforementioned inherent risk. Sierra has never found his footing at the MLB level, and Castano hasn't done much either (though he just got hit in the head with a line drive, ouch), but Gallen and Alcantara, who were both projected to be relievers or back of the rotation starters at best (iirc), both ended up becoming aces. Alcantara in particular looks like a generational type of player. Both players hit probably their 99th percentile projection, not much you can do.
Second, Marcell Ozuna wasn't good (at baseball, not a very good person either as it turns out) and didn't re-sign. Pretty much the worst case scenario overall. So I get, with this in the back of their minds, why some Cardinals fans would be scared of a Soto trade when things like this happen.
But do you think Soto is closer to Ozuna, a guy who had one good year and the Cardinals only took because he was their last option, or to Goldy and Arenado, established stars? My bet is on the latter, and I don't think anyone doubts that Soto would perform wearing the birds on the bat, so that's one half of the trade taken care of. (Also, since the Ozuna trade the Cardinals have essentially completely replaced their talent development and evaluation people, so one would hope guys like Alcantara and Gallen wouldn't slip through the cracks again)
So, do you think that, of the four players the Cardinals send to DC, two of them are going to become stars? That just seems ridiculously unlikely to me. If we think of the package as Gorman, Carlson, Burleson, and Graceffo or Hence, I think Gorman and Carlson will be solid players, but who knows about the other three. If Burleson comes up and is average, and then Graceffo/Hence comes up a couple years later and is also average, which is probably the most likely outcome, then would you be okay with that? I think I would, and the Cardinals definitely would be for 2.4 years of Juan Soto.
I think the most important aspect though is whether the Cardinals can re-sign Soto. If the Cardinals can do that, even if it's on a bridge-style contract until he's 29 or 30, then I think the trade is an unmitigated success pretty much no matter what. If they can't, then it becomes a lot more dependent on how many World Series the Cardinals win in the coming three years and the outcomes of who we send away.
I have a sneaking suspicion that they'll be able to re-sign him though. I think this is another unique advantage that the Cardinals franchise has. Though he seems dedicated to testing the market, what's the point in testing it if there's nowhere better to be? Somehow the Cardinals have been able to convince a surprising amount of the talent they've acquired to stay on the team (heck they convinced Goldy in like 3 days). St. Louis is a great baseball city with a passionate but (relatively) kind fanbase and media, a front office committed to winning for the foreseeable future, and a strong baseball tradition. If you're a top player trying to win championships, where else would you want to go? Soto strikes me as the sort of player who would care more about his legacy than maximizing the amount of money he makes (that's probably part of why he turned down the Nationals' offer in the first place). Given 2.4 seasons and 3 postseason runs, I think St. Louis would win him over eventually.
So, that's my comprehensive thoughts on why the Cardinals trading for Juan Soto is a good idea, for a bunch of reasons. I will be legitimately disappointed if the Cardinals pass him up; I think it's a once-in-a-lifetime opportunity. But, I think the Cardinals' front office is smart enough to understand that, hopefully. Fingers crossed.