The veteran pitcher expects to go to New York on Friday to get his knee drained and to receive a cortisone shot, Kristie Ackert of the New York Daily News reports.
The 38-year-old said he felt pain in his arthritic knee Wednesday during his start against the Baltimore Orioles, according to Ackert. He had surgery on that same knee during the offseason.
However, Yankees manager Aaron Boone isn't worried about the injury.
"I don't expect it to be a long thing," Boone said, according to Bryan Hoch of MLB.com. "This is something we know that we're going to face at different times throughout the year with CC. Hopefully, it's just something that we knock out quickly and hopefully we just miss a turn."
In addition to Sabathia, the Yankees' starting rotation is also missing injured ace Luis Severino, who's yet to throw a pitch in the majors in 2019, and left-hander James Paxton due to knee inflammation.
Sabathia is 3-1 this season with a 3.48 ERA and 34 strikeouts in 41 1/3 innings for the AL East-leading Yankees.
New York's injury issues have been well-documented this season, and the team received some more tough news on Wednesday as slugger Giancarlo Stanton exited his rehab assignment due to left calf tightness. Since landing on the IL on April 1 with a strained left biceps, Stanton has also dealt with a shoulder issue.