The Cubs recalled infielder Chad Tracy from Triple-A Iowa and placed Ramirez on the DL, retroactive to Tuesday. Piniella also sent a message Wednesday to the other players on the roster: If you do well, you'll play.
Piniella met one-on-one in his office at Miller Park with a few of the players before Wednesday's game.
"Whoever's playing the best is going to get the playing time," Piniella said. "I've been very patient. From now on -- and I appreciate the effort everybody's given -- but we're not winning baseball games, and I'm going to play people who I feel give us the best chance to win on that particular day and that's the end of it."
Tracy and Jeff Baker, who started on Wednesday against Milwaukee lefty Randy Wolf, will platoon at third base. Tracy, who opened the season with the big league team, was batting .396 in 26 games at Triple-A Iowa. He has five home runs, eight doubles and 18 RBIs with Iowa, notching his third four-hit game on Tuesday against New Orleans. He hit two solo home runs in that game.
It was difficult to accept being sent to the Minors at first.
"Sure, but you do what you have to do," Tracy said. "You continually have to prove yourself in this game. I took some good at-bats and had some success and hopefully opened some eyes."
"Tracy has been swinging the bat well," Piniella said. "I hope it continues."
Ramirez has been scuffling, batting .168 with five homers and 22 RBIs in 47 games.
"Right now, I'm not helping the team, not helping myself," Ramirez said. "We're going to try to get 100 percent and try to get back to being who I was."
Ramirez has not used the sore thumb as an excuse, but he admitted it's been difficult to grip a bat because of the swelling and discomfort.
"It's hard to hit when you're good enough and 100 percent," Ramirez said. "It makes it even tougher when you're not. I tried to play through it and it didn't work. I guess it's time to let it heal."
The Cubs had talked to Ramirez about going on the disabled list earlier, but he didn't want to.
"I thought I was good enough to play [through it]," he said. "I can't help the team missing two games like I missed the Dodgers series. It just makes sense to rest it now and try to get it 100 percent or at least close to it."
He doesn't consider the time off as a mental break.
"The only way you can get out of a slump is by playing," he said. "That's why I tried to play through it and it didn't work."
He tried to use a donut on the bat when the team was in St. Louis, but that didn't work.
"[Going on the DL] is the right thing to do," he said. "If I can't swing the bat and I can't contribute to this team, there's no sense for me to be playing right now."
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.