King hasn’t pitched since July 9, landing on the injured list with what the team initially called shoulder inflammation. That he required this procedure to address the issue is a bit discouraging, since some pitchers (most prominently Matt Harvey) never regained their effectiveness after bouts with thoracic outlet syndrome. That’s not to say TOS surgery is automatically a crushing blow, however. As one example, the Diamondbacks’ Merrill Kelly underwent a thoracic outlet procedure last September and has been durable (aside from a battle with COVID-19) and essentially as productive this season as he’d been in years prior.
The Rangers have had a below-average relief group this season, but King had been a bright spot before his injury. The southpaw frequently worked multiple innings, tossing 46 frames over 27 appearances. Despite a below-average 20.7% strikeout rate, King posted a 3.52 ERA thanks largely to his ability to keep the ball on the ground. The sinkerballer racked up grounders at a 57% clip, a top thirty mark among the 320 relievers with 20+ innings pitched.
That performance was impressive enough that King was initially reported to be part of the Yankees’ deadline acquisition of Joey Gallo. He was eventually removed from the deal as part of a later reshuffling, with Joely Rodríguez heading to the Bronx instead. (King was already on the IL at the time and didn’t return to pitch this season).
Assuming he’s ready for Spring Training as expected, King should have the inside track at landing a season-opening spot in the Texas bullpen. The 27-year-old isn’t slated to reach arbitration eligibility until after the 2023 campaign at the earliest, and future optional assignments could push back that timeline even further.