PITTSBURGH -- Reds starter Johnny Cueto was cruising in the fifth inning of a tied ballgame against the Pirates, but had to leave with one out after throwing a pitch to Travis Snider due to pain in his right triceps.
Cueto felt he hurt the arm earlier in the fifth inning and he will return to Cincinnati on Sunday to be evaluated by Dr. Timothy Kremcheck.
"I believe that when I threw a changeup to Alvarez, I felt something," Cueto said. "I felt something sharp in my arm."
The Reds removed Cueto in a precautionary move.
"I feel worried because I was feeling really well," Cueto said. "I didn't want to come out of the game. I was pitching so well that I really wanted to stay in that game tonight."
Cueto tossed 4 1/3 innings and surrendered one run on two hits. He threw 52 pitches, 35 for strikes.
Right-hander Alfredo Simon came on in relief of Cueto and allowed a run before escaping the inning. He later gave up another run, taking a loss in the 3-1 game.
The Reds are hoping for the best, as Cueto is 1-0 with a 2.60 ERA.
"We don't know much yet," manager Dusty Baker said. "It's not anything in the elbow and not anything in the shoulder. It's in the belly of the triceps."
George Von Benko is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.