Where is Peter Bourjos?

This season, there have been two Cardinals outfielders who have been healthy and on the roster the entire year. The first is Jason Heyward, who has rebounded nicely after a slow start and is on pace for another 4-5 win season. The other is Peter Bourjos, who, by all indications, has disappeared off the face of the earth.

We all know how the Cardinals' outfield has been decimated by injuries this year. Matt Holliday has been mostly absent from the roster since injuring his quad on June 8th. Jon Jay has made two extended trips to the DL after offseason wrist surgery and has not been the same in the time he has played. And Randal Grichuk has also been on the DL twice this season with separate injuries in his back and his elbow. Since August 17th, the Cardinals have been without all three of these players at the same time, which had not previously happened at any point this season. And yet, Peter Bourjos has not been in the Cardinals' starting lineup since August 13th, which has been his only start this entire month.

For regular readers of this site, I probably don't need to explain why Bourjos' lack of playing time is so puzzling. However, there are many Cardinals fans out there who will make the argument that Bourjos hasn't done anything to deserve more playing time. And if we take a quick look at his stat line for this season, it is easy for lazy thinkers to jump to this conclusion.

Bourjos has been below replacement level this season, according to Fangraphs, with his offense at 21 percent below league average and his defensive metrics surprisingly underwhelming (-5.0 UZR, -4 DRS). Of course, the problem with looking at these numbers is that the sample size is pretty small, especially for the defensive metrics. One season's worth of defensive data can be quite unreliable, even for a starting player, and right now, Bourjos doesn't have anywhere close to the amount of playing time a starter would have. In fact, despite all the injuries in the Cardinals' outfield, Bourjos is on pace to receive even less playing time he did than last season, when the Cardinals' outfielders were healthy pretty much the entire season.

For people who choose to fixate on Bourjos' small sample 2015 stats, there are actually reasons to be somewhat hopeful about his offensive potential. Bourjos is currently running a .280 BABIP, which isn't insanely low but still below his career norm of .306. A little more batted ball luck would certainly make his batting line look less terrible than it currently is. Also, in spite of his low batting average, Bourjos' OBP is just six points below league average due to an above average walk rate. And his .129 ISO, while slightly below league average, is an indication that Bourjos isn't a completely punchless hitter. (For comparison's sake, Jon Jay has a career ISO of .097.)

Of course, Bourjos has a track record of success prior to this season, and this track record should not be ignored, especially when we only have a sample of 208 plate appearances this season. Over his career, Bourjos has a career batting line of .243/.305/.382 with a 92 wRC+ in 1638 plate appearances. While these numbers aren't spectacular, they indicate that Bourjos is more than just a black hole on offense. It should also be noted that in the one season where Bourjos received regular playing time (552 plate appearances in 2011), he hit .271/.327/.438 with a 114 wRC+. While it is likely that Bourjos received regular playing time because of his offensive contributions, it is also possible that he was able to stay locked in offensively because of his consistent playing time.

As most people know, though, much of Bourjos' value comes from his typically excellent defense in center field. Over his career, Bourjos has saved somewhere in the range of 36 (by DRS) and 44.1 (by UZR) runs defensively. His career UZR/150, which is simply UZR scaled to an average number of chances for a season, is an outstanding 15.8, even with his below average numbers in 2015. All told, Bourjos has averaged 3.2 fWAR per 500 plate appearances throughout his career, which is comfortably above league average for position players.

Many people will likely argue that the Bourjos is no longer capable of being the player he once was just a few years ago. Perhaps he has lost a step on defense. Perhaps pitchers have figured out how to consistently exploit a hole in his swing. These may be possible, but I find it hard to believe that at age 28, Bourjos has declined to the point of not being at least a viable fill-in starter in center field. Just last season, Bourjos accumulated 1.7 fWAR in 294 plate appearances, which would make him approximately a three win player with regular playing time.

While there are clearly non-small sample size indicators that suggest that Bourjos is still a valuable player, let's pretend for a moment that his 2015 stats are more indicative than we realize and that he has declined significantly offensively and defensively. In this scenario, Matheny and his coaches have good reason to believe that Bourjos is a significantly worse option in center field than Randal Grichuk, Tommy Pham, and an injured Jon Jay. Perhaps the front office and the coaches have valuable information about Bourjos that is not available to the public, making his lack of playing time justifiable.

Based on the way Bourjos has been managed, it seems pretty clear that the team doesn't believe he has declined defensively. Matheny has consistently utilized Bourjos as a defensive "closer" in center field, inserting him into the game in the last inning or two when the team holds a small lead. This usage pattern is significant, because it suggests that despite his poor 2015 defensive metrics, Bourjos is clearly a better option defensively in center than Grichuk, Jay, and Pham. While we have not seen much of Pham in center field yet, we have good indications that Grichuk and Jay are at least average in center field and quite possible above average. By default, that means that Matheny still sees Bourjos as an above average (if not elite) option defensively in center field. Otherwise, Matheny would have no reason to put Bourjos' inferior bat (compared to Grichuk and a healthy Jay) in the lineup late in games.

On the offensive side of things, Bourjos' struggles may be something to worry about, and while the sample size (at least with the Cardinals) is somewhat large (602 plate appearances), it is not particularly representative of what he could do with normal playing time. Bourjos has never had a long stretch of consistent playing time while with the Cardinals, and it is possible that this has contributed to Bourjos' lack of consistency on offense. Bourjos described the difficulties of being in this situation when he spoke to MLB.com's Jennifer Langosch.

"There was a series against the Mets right after the break when my swing was about as good as my swing has ever felt, and then I don't think I played for another week," Bourjos said. "Then timing becomes hard, and it makes it difficult. It's a tough situation, but you have to do your best with it."

For all of Mike Matheny's talk about getting certain players going and making them feel like they're an important part of the team (I'm paraphrasing past quotes from Matheny here), this approach has not been applied to Bourjos at all. Bourjos has also not been given the chance to build off any success he has managed to have. For example, he broke out of a slump by hitting a home run in Arizona earlier this week, but he has been on the bench again in every game since then.

In addition to receiving sporadic playing time, Bourjos has faced more relief pitching than usual due to his role as a pinch hitter and late game defensive replacement. This is potentially significant because relief pitchers are usually tougher to face for a number of reasons (higher velocity, more specialization). Here are the league wide stats for starters and relievers in 2015.

While the starter/reliever split is relatively small and may not have a dramatic effect on Bourjos, it certainly isn't doing him any favors.

At this point, I have accepted that Peter Bourjos will not be the primary center fielder for the Cardinals going forward, even with Jon Jay and Randal Grichuk on the DL. With that being said, I don't think there is anything wrong with splitting time more evenly between Bourjos and Tommy Pham, who has effectively been the everyday center fielder since Grichuk went on the DL.

The way Matheny has managed Pham, you would think that he was a far superior player to Bourjos, but we don't have much evidence to suggest that this is the case. Pham is a 27-year old rookie with little-to-no prospect pedigree who has been league average offensively and below average defensively in just less than 100 plate appearances at the major league level. I think that Pham could develop into a useful part-time player for this team, but that does not mean he should start every single game in center field when there is a potential 2-4 win center fielder available on the roster.

It is notable that when Matt Holliday returned to the team briefly in late July, the Cardinals' front office opted to send Pham to Triple-A, which seemed like a no-brainer move at the time. However, if John Mozeliak and company truly believed that Pham was a far better player than Bourjos, they could have made a move to keep Pham on the major league roster instead of Bourjos. The team's roster moves (which are made by the front office) seem to suggest that Bourjos is the better player, but the enormous disparity in playing time received by each player (a decision made by the manager) seems to suggest that Pham is the superior player. Because of this, our best guess at explaining the puzzling treatment of Bourjos is that the front office and the manager disagree on how valuable a player he is, but the front office is not willing to force Matheny's hand by making him play Bourjos more often.

Of course, the person who suffers the most from this apparent disagreement is Bourjos himself, who is not getting the opportunity to live up to his potential and contribute fully to this team. I cannot help but feel bad for the guy, who by all accounts is handling the situation like a true professional. Given the fact that Bourjos has been treated like this for nearly two full seasons now, I feel like I am beating a dead horse at this point and should not expect anything to change. Still, when the team loses its two primary options in center field, it shouldn't be unreasonable to expect an increase in playing time for the next best center fielder available.