Burnes exited Thursday's start with a trainer and appeared to be in discomfort, Adam McCalvy of MLB.com reports.
Burnes recorded the first out of the eighth inning when he was visited on the mound by a team trainer. It's possible that he was lifted as a precaution, as he had already thrown 94 pitches and was deep into the game. Burnes dominated the Pirates prior to his exit, allowing only one earned run on four hits and one walk while striking out four.