ATLANTA -- Cliff Lee could be back in the Phillies' rotation early next week.

On Wednesday, Lee threw his first bullpen session since straining his left oblique April 18 in San Francisco. The lefty reported no pain and said if he feels fine Thursday, he is scheduled to throw a second bullpen session Saturday.

Assuming that goes well, he could pitch for the Phillies a few days later at Citizens Bank Park.

"I feel good about it," Lee said. "If things go well, it's one more bullpen and then the game. That's the plan for now, but that's all flexible."

Lee said he has been pain-free recently.

"It did linger a little bit," he said. "But it's slowly gotten better. But the last two days have been drastically better than the four or five days before that. It just kind of plateaued and stayed the same. But the last two have been good."

Asked if it is safe to say the problem is gone, Lee said, "Every throw, I didn't feel anything. There are a couple exercises I do where I can barely feel it, but compared to how it was before, it's pretty safe to say it's on its way to being gone."

Back strain forces Thome to disabled list

ATLANTA -- It surprised nobody Wednesday when the Phillies placed Jim Thome on the disabled list with a strained lower back.

It had to be done. Thome had not played since he injured his back Saturday, which had left Charlie Manuel short a player on the bench. But with Thome on the 15-day DL, the Phillies recalled catcher Erik Kratz to take his place.

Kratz was scheduled to be in uniform in time for Wednesday's game against the Braves at Turner Field. He hit .294 with four doubles, three home runs, nine RBIs and an .882 on-base-plus-slugging percentage for Triple-A Lehigh Valley.

"We felt like he earned a shot," Manuel said. "He's been hitting the ball good. Our reports have been good on him. It gives us a third catcher. It gives us a guy who can hit the ball out of the yard, a bat off the bench, stuff like that. A righty."

Thome is in Clearwater, Fla., where he will rehab. He can get limitless at-bats there, if he plays in extended Spring Training games. That is the plan, and that is expected to be the greatest benefit to Thome. He is just 2-for-18 with 10 strikeouts.

Manuel has said Thome needs more at-bats to get his timing at the plate. That shouldn't be a problem in Clearwater.

"Yeah, it's definitely going to help him," Manuel said. "He's going to see some pitching. In extended spring he'll see some live pitching."

Manuel said he still plans to play Thome at first base once he rejoins the team.

"I think that we need to play him," the manager said. "I think we're going to have to play him. When Ryan Howard comes back, more than likely every now and then he's definitely going to need a blow. He's coming off a serious injury, and the fact he hasn't had any [Spring Training]. ... To put him out there at first, you're going to have to monitor him a little bit. And that would hopefully be Thome, if he's ready to hit."

Worth noting

• Triple-A Lehigh Valley outfielder Domonic Brown strained his left hamstring Wednesday. He is day to day. Brown is hitting .247 with six doubles, one triple, 11 RBIs and a .629 OPS in 24 games with the IronPigs.

• Right-hander David Herndon, who is on the 15-day disabled list, has a strained pronator tendon. He is not throwing for three weeks.

• Second baseman Chase Utley is scheduled to join the Phillies this weekend in Washington. It is possible Utley could then head to Clearwater, Fla., to begin his rehab.

• Class A Clearwater left-hander Jesse Biddle, who was the team's first-round pick in the 2010 First-Year Player Draft, got hit with a line drive on his left forearm Tuesday. He left the game for precautionary reasons.

• The Phillies named Double-A Reading first baseman Darin Ruf and right-hander Tyler Cloyd their Minor League Player and Pitcher of the Month, respectively.

Ruf, who was selected by the Phillies in the 20th round of the 2009 First-Year Player Draft, hit .378 with 31 hits in 23 games in April. Cloyd, selected in the 18th round in 2008, went 4-0 with a 1.45 ERA in five games with Triple-A Lehigh Valley and Reading.