PHOENIX -- Alfonso Soriano was smiling again on Wednesday.

The Cubs activated Soriano from the disabled list, and he was leading off and starting in left field for the series finale against the Arizona Diamondbacks.

"We've missed Alfonso," Cubs manager Lou Piniella said.

"I woke up this morning very early because I wanted to come to the ballpark so bad to play today," Soriano said. "I don't even think about my hand any more. It's like nothing happened."

Soriano has been out since June 11 when he was hit on the left hand by a pitch by Atlanta's Jeff Bennett. He suffered a fracture of the fourth metacarpal, and the Cubs have gone 16-18 without him in the lineup.

"Hopefully, he can swing the bat the way he's capable of soon," Piniella said of Soriano, who was batting .283 with 15 homers and 40 RBIs in 51 games before he was injured.

"I have to be careful because it's been seven weeks since I've been playing," Soriano said. "I don't want to do too much -- I want to do what I can do. I want to go out and have fun and do what I can do."

Soriano, expected to wear a brace on his left hand, wasn't worried that the injury will affect his power.

"I don't feel pain at all, but I've never had this injury before so I don't know how I'll come back," Soriano said. "The most important thing is no pain. I feel good at the plate, I swung the bat well. We'll see in the game. It's never happened before, and this is a new experience for me."

He made two rehab starts this week, and was 1-for-3 Tuesday night in Tucson.

The Cubs also activated left-handed reliever Scott Eyre from the disabled list. Eyre, who was 2-0 with a 4.91 ERA in 18 games, had been sidelined since June 27 because of a strained left groin.

To make room on the roster, Kevin Hart and Micah Hoffpauir were optioned to Triple-A Iowa. Hart has not been as effective as he was last season, and on Tuesday, faced nine batters and gave up four runs on two hits and three walks in two-thirds of an inning.

"It's a mystery -- he's got good stuff," Piniella said of Hart's struggles. "He's just got to figure it out. He's got the stuff to do it."

Hart will join Iowa's rotation.

"When you come back up, you want to stay and you try to do too much," Hart said. "I have to go back and do what I do well which is attacking hitters. Mentally, I feel I still have the ability to do it."

When he was called up before, Hart struggled a bit, then went back to Iowa and dominated. Confidence isn't the problem.

"I feel like I'm giving people too much credit, and by doing that, I'm putting myself in a situation where it's tough to succeed," Hart said. "You walk the leadoff guy, and it's tough to succeed. Yesterday, I drew the line and said enough is enough. It was one of those situations where that was it. That's enough. You worry about failure, and then when you fail, it's like, 'Why did I worry about that?'

"I know I can pitch here," he said. "I've done it before. It's one of those things where I have to get it rolling. This team can use me because the bullpen is an important thing down the stretch."

Hoffpauir, called up Friday, was batting .378 in 19 games with the big league team this season, but was 0-for-2 in one game this month.