PHILADELPHIA -- Cole Hamels said he feels fine and expects to be back in the Phillies' rotation next week.

But the Phillies said Tuesday he will miss at least one start because of inflammation in the back of his left shoulder, which is worth watching with a little more than six weeks remaining before the postseason. Hamels' velocity has dropped in each of his previous five starts, which prompted him to have an MRI exam Monday.

Hamels said Tuesday the results showed "everything I thought was not wrong. Everything looked good, and that's kind of what the feeling was."

Hamels, who did not receive a cortisone injection, said he will begin throwing again Wednesday with a bullpen session possibly Friday. If he continues to feel OK, he could be back in the rotation as early as Monday against the New York Mets at Citizens Bank Park.

Why is Hamels unconcerned about the inflammation?

"We've got five pitchers who I think all have inflammation in their shoulders right now," he said.

Phillies general manager Ruben Amaro Jr. said the Phillies compared Monday's MRI results with the MRI results Hamels received before he signed his three-year, $20.5 million contract extension before the 2009 season. Amaro said there were no changes, meaning they found no structural damage to the shoulder.

Hamels said he isn't sure what limitations he will have upon his return.

"Trying to throw 120 pitches would be a little difficult," he said. "It's just going out and making one pitch at a time."

Amaro sounded cool to the idea of employing a six-man rotation to give Hamels, Roy Halladay and Cliff Lee a little extra rest before the end of the season, but he did not shoot down the idea completely.

"We can't take anything for granted," Amaro said. "We've still got a lot of baseball left. Our goal is to still win the division. We've got to have these guys pitch. At this time, we'll try to be cognizant of the workload they've had, because they've had a pretty significant one."

Polanco heads to DL with sports hernia

PHILADELPHIA -- Placido Polanco will try to finish the season playing with a sports hernia injury.

He was placed on the 15-day disabled list following Tuesday's 3-2 loss to Arizona, retroactive to Aug. 7. The Phillies want to give Polanco a few more days to rest the injury, which means he could be activated as early as Monday against the New York Mets at Citizens Bank Park. The Phillies called up right-hander Michael Schwimer from Triple-A Lehigh Valley to take Polanco's spot on the 25-man roster.

Polanco said he has ruled out surgery, which the Phillies said was an option last week.

"If I have surgery, I'm out for the year," he said.

Polanco said on a 1-10 scale the pain is a six. He said he could play like that the remainder of the season, including the postseason.

Worth noting

• Right-hander Joe Blanton (right elbow inflammation) continues to play catch. He hopes to begin throwing off a mound as early as next week. He remains hopeful he can pitch in the bullpen before the end of the season. Right-hander Jose Contreras (strained right forearm) also continues to play catch. Phillies general manager Ruben Amaro Jr. said he is pleased with the progress of Contreras and Blanton. "We're going to take it pretty slow with them," he said. "There's no rush. We want to make sure they're healthy when they get back on the mound."

• The Phillies signed their two top picks in the 2011 First-Year Player Draft -- outfielder Larry Greene and shortstop Roman Quinn. The Phillies signed 30 of their 50 picks, including nine of their first 10 selections.