Should Cubs be worried about Brennen Davis’ lingering back issues?

Unless you follow the English Premier League (“soccer” in the US, “football” everywhere else) you probably haven’t heard of Adam Forshaw. In fact, even if you do follow the EPL you might not have heard of Forshaw. He’s the type of gritty overachiever who earns respect from teammates and the local fans alike even though (or perhaps because) he is by no means a star. He has no exact analog in baseball; he has the positive can-do vibe of a middle infielder but he’s much more important that, yet the box score seldom advertises his achievements. Think, maybe, something between some guys Cubs fans are surely familiar with: David Bote and Ben Zobrist.

But Forshaw has one thing directly in common with current Chicago Cubs prospect Brennen Davis: doctors could not figure him out. Forshaw went to many different specialists over many months in an effort to ascertain the cause of the stabbing pain in his right hip. He had four surgeries. He even had a few teeth removed. The fifth operation was the one that finally worked; Forshaw had to fly to a specialist clinic in Colorado to get it done. Forshaw returned to the pitch after nearly 700 days.

There’s no reason to believe Davis will be out nearly as long, but like Forshaw, his body concealed a medical mystery: a strange mass of blood vessels near the base of his spine. Davis explained his saga in an interview with Marquee last August, worth listening to if you missed it. Davis’ medical mystery tour was not nearly as long as Forshaw’s (and Davis, as far as we know, still has all his teeth) but in both cases some of the best medical minds in sports struggled to find the cause of a debilitating injury.

Not long after the Marquee interview, Davis began terrorizing pitchers in the Arizona Fall League to the tune of a 1.048 OPS.  But not long after the fall league season began, injury claimed Davis once more, and it it’s his back again. No word yet on whether this current issue is related to the earlier surgery, the underlying ailment, or none of the above.

His return to the field had not been triumphant prior to his fall league stint. After a few warm-up gigs in A-ball, Davis arrived in Iowa on Aug. 30. He would put up a .705 OPS the rest of way, hitting just two homers over the final month of the season. This was an improvement over his performance at the beginning of the season when he was still in pain, but certainly not the breakout he would later achieve, albeit briefly, in the hitter-friendly Arizona desert.

Davis’ fate will go a long way toward determining the Cubs outfield depth chart over the next few seasons. But it also will test the organization’s ability to rebuild at the rate they would like. A player’s contribution to victory is the product of his physical ability and his experience. While experience rises through a player’s career, physical ability might already be declining by the time a plyer makes the majors. What’s different today is that advances in sports science, nutrition and allied fields mean that players coming into the game will, other things being equal, physically decline more slowly than the veterans they are replacing did in their own primes.

Thus, players hitting the majors today will probably maintain their top productivity for a little bit longer than the guys that got there earlier. This is another reason why young players are so valuable, even beyond the fact they are still getting underpaid. (This upward bending of the aging curve isn’t new, see here and scroll down to Chart II; more recent wonkery on aging curves can be found here, though this article does not break the data out by separate eras.)

Chicago Cubs could use a healthy Brennen Davis in 2023

The medical mystery menaces this happy development pattern. The longer injuries delay a player’s arrival in the majors, the less the team will benefit from his peak production, which may itself be less than it would have been without the mysterious injury. The Cubs may be able to find other outfielders to replace Davis on the depth chart, but they can never get that draft pick back. An uninjured Davis would have been in the majors by now, allowing the Cubs front office to assess whether he solves a roster construction problem or not.

Brennen Davis will continue to receive excellent medical care – some of the best available on Sol III – not because the Cubs are kindly, but because his physical gifts make Davis worth the investment. There will be awful medical surprises as long as humans are around to be surprised. But as medical science begins to conquer the ailments that would have finished off players a generation ago, more strange-but-true injuries will come to light. The team that can resolve such issues with the greatest efficiency (or even better, find a way to discover them in advance) will have an edge. The MBAs have taken over the game, but the MDs might not be far behind