I'm cautious-at-best about both Jaime Garcia and Joe Kelly's immediate prospects, and the bullpen is not very good. But the Cardinals' consistently weird pitching, and all the depth they've gathered up everywhere else in the lineup, has made it easy to forget just how precarious this infield is. Facebook memes (did you know a black guy is the best golfer and a white guy is the best rapper? Crazy world, bro) have suggested to me that the best way of illustrating a point like this is to remove peoples' names and exaggerate for effect, like so:
The best player in the Cardinals' infield is a 34-year-old shortstop who had an OPS+ of 80 last year and, before 2012, hadn't played 100 games in a season since 2009. DRS thinks he's been excellent as a shortstop over his career, and UZR not especially good, but if you assume he's average this year—as a 34-year-old shortstop—he's been just about average. He's got three extra-base hits in his last 50 games, which is not great.
At second base the Cardinals have a left-handed hitter who would make for an interesting platoon solution there except that he is not a very good second baseman. (Which is not to take away from his major achievement, which is having become a second baseman at all.) He's coming off two bad years—in which he was not even a very interesting platoon solution—after putting together two-and-a-half good ones.
Behind the both of them is a left-handed utility infielder who broke in as a third baseman and has moved backward, by necessity, up the defensive spectrum. He hits about like the Interesting Platoon Solution, except he didn't have so far to go to become a second baseman and he's shown no platoon split so far. (Which is good, because right now he and IPS are locked in a Chris Duncan/Rick Ankiel-level Platoon of Desperation, in which the better defender gamely takes the half of the platoon in which they're both probably overmatched. Sorry, an Ungainly Coach's Son/Converted-Pitcher-Slugger Platoon of Desperation.)
Those are the three main pieces of the Cardinals' infield, and given how terribly they fit together I can't blame the team for dumping Super-Fast-Anxiety-Attack, on whom it had clearly given up; whatever you think of these three suspects, there's a hole exactly the size of a right-handed hitting natural shortstop between them, and this team needed one Handsome Ex-Catcher and Young Mr. Mackey from South Park, Maybe (it came up on Netflix last night and I was struck) were willing to play aggressively.
Now that the Cardinals have all their pieces in good standing, again, and we're not debating Tyler Greene's nebulous upside or mental state, it's a little easier to ask whether all those pieces are competent, in addition to being present. I'm more than a little worried about it—for any of these players to be average, right now, you have to make possibly unrealistic assumptions about their defense.
You have to assume Rafael Furcal both hasn't lost a step and had the above-average step in 2009, say, to begin with; you have to assume Skip Schumaker is really an average second baseman, now; you have to assume Daniel Descalso is as good as he looks despite not being a shortstop and that Ryan Jackson is above-above-average, if not quite Boogian.
Some or all of these things might be true, but on a certain level defensive evaluation will always feel like a teacher's-discretion sort of slush fund for bloggers and blog-commenters—Skip Schumaker's defense gets more average or more terrible depending on what it is Mozeliak and Matheny are proposing to do with him, and so on. I think it's safer to just say that this unit is probably below average, and leave it at that.
Which is another reason to be all right with the Tyler Greene trade, whatever you think he might do in Houston—this is a team that needs to experiment with its infield as much as its personnel allows, and Greene's stagnant position at the end of the bench was keeping that from happening.
It's a harder trick to pull off in the infield than it is in the bullpen, where I'm guessing the three-lefty configuration is nearly out of runway; the Cardinals' major chances at reimagining this situation lay—and lie still, I guess—on the trade market. But the Cardinals had this move left to make, and they've made it.