CHICAGO -- The Cubs activated Aramis Ramirez from the disabled list Friday and hope the third baseman returns to his 2009 production, not what he did earlier this season.

Ramirez has been sidelined since June 8 because of a sprained left thumb. He was batting .168 in 47 games before he was forced out, with five homers and 22 RBIs in 47 games.

"I think the only way you can get out of a slump is by playing," Ramirez said Friday. "By sitting, you're not helping yourself. It's a long season, and the only way to get back is by playing the game."

To make room for Ramirez, infielder Chad Tracy was designated for assignment. Tracy, in his first season with Chicago, was batting .250 in 28 games with five RBIs. He was 1-for-14 as a pinch-hitter.

Tracy opened the season on the Cubs' roster, and had two hits in 15 at-bats in April (.188) before he was sent to Triple-A Iowa on May 6. In 26 games for in the Minors, Tracy batted .396 with eight doubles, five homers and 18 RBIs.

"He did a nice job here, and I hope he catches on with another team," Cubs manager Lou Piniella said of Tracy.

The Cubs are eager to see if the time off and a change with his grip helps Ramirez. He batted .317 last season despite missing two months because of a separated shoulder. Ramirez finished with 65 RBIs in 82 games, batting .425 with runners in scoring position.

"He's been swinging the bat well," Piniella said. "There's no reason he can't step in there and swing the bat and help us offensively."

Maybe the time off will help not only physically but mentally.

"Sometimes it clears your mind," Piniella said. "Sometimes it becomes as much mental as anything else."

Ramirez said he's more comfortable after making the changes in his grip.

"I made the adjustment, and we'll see how it feels now in the game," he said.

The Cubs have fallen eight games back in the National League Central. Part of the reason is Ramirez's struggles as well as those of Derrek Lee, who was batting .233 entering Friday.

"It's hard to be a consistent offensive productive club day in and day out when your [third and fourth hitters] aren't playing up to their standards, which I think they'd tell you," Cubs general manager Jim Hendry said. "Hopefully, Aramis gets going, stays healthy and gets back being the guy we've seen for six or seven years now. Derrek is showing signs of it. He's probably not pleased with his first half and is certainly capable of getting on a roll.

"If you take any club and get the production we've had in the first half from [the three and four hitters], it's hard to maintain," Hendry said. "Other guys start pressing in clutch situations. It's not easy to hit, and it's not easy to hit in the clutch."

As a team, the Cubs were batting .250 with runners in scoring position and ranked 13th in the National League in runs scored. Ramirez was hitting .172 this season with RISP, and the Cubs' third basemen combined were batting .220.

"I just wanted to get healthy and try to get my swing back," Ramirez said.