Pittsburgh Pirates starter Gerrit Cole exited Friday's start against the St. Louis Cardinals in the third inning due to right triceps tightness, the team announced.
He is being treated and will be re-examined on Saturday.
Cole allowed a hit in the third before he walked off the mound. The team has not disclosed the extent of his injury.
He entered Friday night's game with a 2.77 ERA, 5–4 record and 55 strikeouts in 68 1/3 innings.
Reliever A.J. Schugel replaced Cole.
The Pirates are 32–28 and in second place in the National League Central.