The Yankees will once again be without Nestor Cortes in the lineup due to injury after placing the starting pitcher on the 15-day injured list with a left rotator cuff strain, the team announced Friday.

Cortes, 28, later announced he will be shut down for “about a month,” casting real doubt on his ability to return this season. In regards to the injury potentially being season-ending, Yankees manager Aaron Boone told reporters it would “probably be tough” for the left-hander to come back this season.

New York’s decision, which is retroactive to Tuesday, comes on the heels of Cortes (5–2) working his way back from the same injury that previously landed him on the 60-day IL on June 8.

After missing over two months of action, Cortes re-joined the Yankees on Aug. 5, where he logged eight strikeouts in four innings and one run in a 3–1 win over the Astros.

With Cortes out for the foreseeable future, the last-place Yankees (59–56) will have to find more ways to make ends meet in their already battered bullpen, which is currently without Carlos Rodón and Domingo Germán.

Entering Saturday, right-hander Jhony Brito (4–5), who was called up by New York on Friday in a corresponding move, is expected to start in Cortes’s place for a road game against the Marlins.