"He pulled it pretty good," Brewers manager Ron Roenicke said. "We'll know a little bit more [on Sunday], but he felt a pop."
Ramirez, who had hit a long solo home run the previous inning to give Milwaukee a 4-2 lead, ranged a few steps to his left to field a Yangervis Solarte grounder. Ramirez flipped the baseball to second base for a force play but grimaced in pain. Before head athletic trainer Dan Wright could even get to the scene to investigate, Ramirez was walking to the dugout.
He was replaced by Jeff Bianchi, who is one of the candidates to start Sunday's series finale in Ramirez's place.
If Ramirez hits the DL, the Brewers have some decisions to make. Right fielder Ryan Braun is eligible to be activated before Tuesday's game against the Pirates, and the best-case scenario has the Brewers getting through Sunday one man short, then swapping Braun for Ramirez before Tuesday. But if Braun needs more time, the Brewers would have to promote a player from Triple-A Nashville, especially because leadoff hitter Carlos Gomez still has a suspension looming. Gomez had an appeal hearing Friday and should get a result from Major League Baseball by Monday.
"We'll have to figure that out," Roenicke said. "With Ryan coming off, hopefully he's off Tuesday. If it waits until Wednesday, we'll have to figure out what we're going to do. I don't know, we've got a lot to talk about here."
Ramirez has played parts of 17 seasons in the Major Leagues, and he said this is his first hamstring issue.
"It's pretty sore right now," Ramirez said. "I don't know how bad it is. It was right when I stretched to get the ball. I stretched my hamstring. Hopefully, I feel better tomorrow."
He has been healthy this season other than missing two games last week with a bruised left elbow, but has been battling one of the worst hitting slumps of his career. Ramirez had four hits in his previous 52 at-bats entering Saturday night, when he singled in the first inning and homered in the third.
"That's the thing," Roenicke said. "We talk about him swinging the bat better. He comes out, does that and all of a sudden he's down. That's a tough one."
Adam McCalvy is a reporter for MLB.com. Read his blog, Brew Beat, and follow him on Twitter at @AdamMcCalvy. This story was not subject to the approval of Major League Baseball or its clubs.