Sacramento RiverCats starting pitcher Sean Gallagher left the game after the first inning Thursday night with a left knee injury.

The severity of Gallagher’s injury has not yet been determined, according to the RiverCats. Gallagher, who is 1-0 with a 1.74 ERA in Triple-A and has had a couple of stints with the A’s this year, gave up two hits and one run during the game Sacramento eventually won 19-10.