After losing out on Jason Heyward a little over a week ago, John Mozeliak has made clear that the Cardinals are perfectly comfortable sticking with their in-house options: Matt Holliday, Randal Grichuk, Tommy Pham, and Stephen Piscotty. (Brandon Moss is also capable of playing in the outfield but figures to receive more time at first base.) While I think that all four of these players are capable of handling a starting job, I am not sure I completely buy Mozeliak's statements about standing pat. The Cardinals presumably have a price that they would be willing to pay for players like Yoenis Cespedes, Justin Upton, and Alex Gordon, and while it may be unlikely that the price for these players drops into the Cardinals' range, we cannot rule out this possibility, especially the longer these players remain unsigned.
The biggest argument against signing one of the remaining free agent outfielders is that none of the players available represent a big enough upgrade over the Cardinals' in-house options. This is why Jason Heyward was such an appealing option. He would have been a 3-4 win upgrade over the Cardinals' in-house options, and he would have been under contract during his peak years. If the Cardinals were to sign one of the remaining free agent outfielders, they would have a crowded outfield in 2016 featuring five good but non-elite players. The marginal value they would receive from the outfielder they signed would be limited.
This argument may only hold true for one year, though, especially if the Cardinals decline Matt Holliday's 2017 option. Holliday is projected by Steamer to be worth 2.1 WAR in 2016. With another year of decline, it may be a stretch to envision Holliday being worth $17 million in 2017. If Holliday and Moss are gone after next year, the Cardinals' only outfield options for 2017 would be Piscotty, Grichuk, and Pham. Perhaps Charlie Tilson or Anthony Garcia will be in the major leagues at that point, but neither of these players projects to be more than a bench player. Unless we believe that Piscotty, Pham, and Grichuk are all good enough to be full-time starters in 2017, the Cardinals may have an opening for a full-time outfielder next offseason.
If the Cardinals are happy with the outfielders that they currently have, then they could simply wait a year and sign another outfielder when they know they will actually need one. The only problem with this approach is that there may not be any good outfielders on the free agent market a year from now. The only players of note who will be available in a year are Josh Reddick, Carlos Gomez, and Jose Bautista. Reddick is not quite on the same level as the Upton/Cespedes/Gordon types, as he has not produced more than 3 fWAR in a since 2012. Gomez has elite potential, as he produced a total of 13.1 fWAR in 2013 and 2014 through a combination of elite center field defense and solidly above average offense. He was not the same in 2015, though, in large part due to injuries, and it remains to be seen whether he can continue to perform at such an elite level. Bautista has been the most consistent of the three, but he will be 36 after next season and would probably not be a good fit for a National League team given his defensive struggles.
Unless another player emerges in an unexpected way in his walk year, it appears that the Cardinals will have difficulty finding an above average outfielder on the free agent market a year from now. For this reason, they should at least be open minded about signing one of the remaining free agent outfielders this offseason. In a weird way, this kind of signing may provide more of an upgrade for the Cardinals in 2017 and beyond than in 2016, even if this player is more productive overall in 2016.
All of this will depend on how the Cardinals evaluate their current outfielders, both at the major and minor league levels. They must first decide whether Holliday will be worth his 2017 option, as his presence on the team that year would seem to lessen the need for an extra outfielder. In addition, they must determine whether players like Piscotty, Grichuk, and Pham are best suited for everyday or part-time roles going forward. Lastly, the Cardinals must evaluate their minor league options and determine if they will be able to fill their outfield spots internally.
At this point in time, my guess is that Holliday will not be worth his 2017 option, especially given his recent injury issues and his rapidly declining defensive ability. I also question whether all three of Piscotty, Grichuk, and Pham can be full-time players in 2017. There are enough questions surrounding these players (injury history, BABIP regression, questionable plate discipline) that it might be best to see these three players as capable of filling (at most) two starting spots. I also do not see any outfielders in the Cardinals' minor league system that are capable of seizing a starting job any time in the near future.
If the Cardinals have a similar assessment of their outfield situation over the next few years, then it appears as though they will have to sign at least one free agent outfielder either this offseason or next offseason, unless they are able to pull off a trade. Given the options available a year from now, this offseason may be their best chance to bring in an impact player capable of holding down a starting outfield spot for the next few years. If the Cardinals can wait things out this offseason and find a situation where one of the top outfielders is willing to sign for less than expected, they should not hesitate to jump at this opportunity.