Royals top pitching prospect Kyle Zimmer has suffered another setback this season, having pitched just 5 2/3 innings before being shut down in May for the vaguely described "arm fatigue." Today, Soren Petro of 810 WHB is reporting that Zimmer will get a procedure done for thoracic outlet syndrome. It it the same procedure that recently caused Mets pitcher Matt Harvey to be shut down for the year.
@MK_uselessinfo Interview with J.J. Picollo coming today in The Program. Called it "the better of the two" types of procedures for TOS.— Soren Petro (@theprogramkc) July 19, 2016
Thoracic outlet syndrome is a rare diagnosis in baseball that affects nerves and blood getting to the arm. It can cause pain and discomfort and has been difficult to diagnose, which is likely why Zimmer was out for so long with an undiagnosed injury. The procedure usually involved removing a rib, to allow greater flow of blood and more room for nerves.
Nick Lampe at Beyond the Box Score recently took a look at recoveries from thoracic outlet syndrome, concluding:
The injury has the potential to seriously hurt a pitcher's velocity, although this hasn't been the case in all situations....
The biggest area these pitchers seemed to struggle was with their command, both in and out of the strike zone. This manifested itself in slightly higher walk rates, a lower percentage of pitches in the strike zone, and hard contact on pitchers that were in the strike zone, including abnormally high home run rates.
There aren't a lot of pitchers who have had this injury, but the track record isn't good. Counting on a pitcher who has been through this injury is a terrifying proposition, especially considering the fact that the pitchers in this article are some of the most injury-prone players in recent memory.
Among the players to be diagnosed with thoracic outlet syndrome including Kenny Rogers, Hank Blalock, Jamie Garcia, Josh Beckett, Shaun Marcum, and Chris Carpenter.
Zimmer has been afflicted with numerous injuries since the Royals made him the fifth overall pick in 2012. He had an elbow cleanout in 2012, then missed nearly all of the 2014 season with a lat injury. After that season, he had a shoulder debridement of his rotator cuff and labrum. He has pitched just 222 1/3 innings in five professional seasons.