An MRI taken Saturday morning revealed that Chapman has no structural damage in his shoulder, sources told ESPN's Marly Rivera. Yankees GM Brian Cashman said Sunday that Chapman won't pitch in a game for at least four weeks.
Chapman told the Yankees he had a similar condition in 2012 when he pitched for the Reds, sources told ESPN's Buster Olney.
In the short term, Dellin Betanceswill replace Chapman as the team's closer.
Chapman gave up a two-out RBI single by Houston's Josh Reddick in the ninth inning Friday night, shook his pitching arm and was checked by head athletic trainer Steve Donohue on the mound moments later after throwing his 22nd pitch. The left-hander initially remained in the game, then was removed after allowing a single to Jose Altuve.
"He said he was fine. Nothing. No pain," manager Joe Girardi said after the game.
It was Chapman's first outing since blowing a three-run lead in the ninth inning last Sunday against the Chicago Cubs.
The four-time All-Star's average fastball velocity has dropped from a major league high 100.9 mph last year to 98.2 mph this year, according to MLB's Statcast.
The Yankees signed the 29-year-old Chapman to a five-year, $85 million contract this offseason, even as Yankees GM Brian Cashman acknowledged the volatility of relievers over the long term.
Chapman has seven saves, but a 3.55 ERA in 12 2/3 innings this season. His strikeout rate of 14.9 is still way above average.
The Yankees first acquired Chapman in the offseason before the 2016 season by taking advantage of the Reds' desperation to trade him because of a domestic violence incident that hung over his head and his large salary. The Yankees sent four not highly regarded prospects for Chapman and then flipped him to the Cubs before the trade deadline in a deal that resulted in the acquisition of Gleyber Torres, who is considered the second-best prospect in baseball, according to ESPN's Keith Law.
The Yankees recalled Chad Green from Triple-A Scranton/Wilkes-Barre to replace Chapman in the bullpen.
Information from The Associated Press was used in this report.