Mat Latos was escorted off the mound in the middle of an at bat by Alfonso Soriano in the fifth inning. He was scheduled to go six.
He appeared to have something wrong with his left leg, the one he lands on.
Paul Lessard and Dusty Baker went out to the mound and decided to remove him from game.
Latos was supposed to pitch six innings today but fell short, working 4 2/3 innings and allowed four hits and three runs, (two earned).
"He is day-to-day," Dusty Baker said.
The Reds flag went up three batters earlier when Latos walked opposing pitcher, Matt Garza.
"We thought it was his knee. He kept landing on the hard ground on the mound. We asked (catcher Dioner) Navarro if he was alright. He wanted to finish but we told him no. We have too many pitchers going down We're going to use caution."