There’s no two ways about it: Willi Castro has drastically underperformed since being acquired by the Chicago Cubs at the trade deadline. It was easy to dream on the utility player being used all over the diamond to give some much-needed rest to the regulars. However, a .159/.205/.246 batting line since joining his new team makes it difficult to justify playing him any more than is absolutely necessary. 

This particularly stings because it feels like the Cubs have really struggled to build a decent bench for a few years now. During that same timeframe, they have had one of the better and most consistent starting nines in baseball. Take this year, for example. The Cubs have exactly nine position players who have accumulated at least one WAR at FanGraphs. They’re the ones you’d think: Carson Kelly, Matt Shaw, Dansby Swanson, Nico Hoerner, Michael Busch, Ian Happ, Pete Crow-Armstrong, Kyle Tucker, and Seiya Suzuki. 

Only three other teams in baseball can claim this, though admittedly, a few others will likely reach the mark by the end of the season. The three teams are the Milwaukee Brewers, Boston Red Sox, and the Toronto Blue Jays. At first glance, I’d say that’s not a bad list of teams to be grouped with this season! All of those teams will be playing October baseball, barring a major meltdown. 

Between those four teams, the Cubs have accumulated the most FanGraphs WAR among their top nine players, and those top nine players have taken the greatest percentage of their team’s plate appearances this season:

Team

Top-Nine fWAR

% of PAs taken by top nine

Blue Jays

26.5

77.5%

Brewers

24.7

68.7%

Cubs

27.1

86.7%

Red Sox

23.4

69.8%

Frankly, it’s not particularly close, and this chart gives me two takeaways. One is that the Cubs have one of the most productive group of starters in baseball, and they ride those guys hard. The other is that the Cubs have been pretty fortunate in the injury department on this side of the ball. Ian Happ is the only member of the Cubs’ usual starting lineup that has spent any time on the injured list. 

Have the Cubs struggled in building a bench because they’ve had issues finding good roster fits? Or have they had issues because they simply can’t afford to give any bench players consistent plate appearances thanks to such a productive core group of position players?

Which brings me all the way back to Castro. He received just 60 plate appearances in August, the least he has received in a calendar month in two years. It’s really hard to go from being an everyday player, receiving 100 or so plate appearances per month, to a part-time player receiving only 60. Looking briefly at Castro’s batted ball data would certainly suggest he is having issues timing up the baseball. All stats courtesy of FanGraphs:

Team

Pull%

Center%

Oppo%

With Twins

40.2%

38.4%

21.5%

With Cubs

24.5%

43.4%

32.1%

Perhaps fittingly, it’s been Castro’s performance against fastballs that has really suffered. Against four-seam fastballs, the utility man had a 141 wRC+ with the Twins. That has fallen to -56 with the Cubs. That is not a typo. Castro has yet to notch a hit against a four-seam fastball since joining the North Siders.

There are a few ways you can point your finger in this situation. I don’t care how infrequently he is playing, Castro needs to be better than he has been, even if it isn’t quite as good as he was with the Twins. Craig Counsell could probably do a better job of keeping his bench involved, too. That’s just so hard to do when you have so many productive regulars, and so many unproductive bench guys. Jed Hoyer could probably do a better job of building the bench. The counterpoint to that, though, is that Castro was the theoretical perfect fit. And even that isn’t working. Or, perhaps it’s really hard to be a productive big leaguer with such limited playing time.

The most likely explanation is usually a combination of all of those things. With some of the injuries starting to accumulate for the Cubs, and their playoff position looking increasingly secure, perhaps Castro can find a groove with some increased playing time going forward. His presence on this team is invaluable, even if his production has been worth nearly no value thus far; getting him going would give Counsell a 10th guy to rely on, something the Cubs haven’t had in quite some time.