PHILADELPHIA - Ryan Howard seemed healthy when he hit a 439-foot home run Friday night.

The Phillies first baseman was anything but, however. Even on that swing, his inflamed left knee ached.

Howard went on the disabled list Saturday night. He will undergo an MRI today.

"We'll see if there's been any drastic changes and then try to come up with a plan," Howard said. "We'll see what happens. As far as surgery or (cortisone) injections it's too early to tell."

Howard's knee has hurt for much of the season. He also underwent an MRI in May.

Howard was in the starting lineup Saturday night, but was pulled from the lineup and placed on the disabled list after fielding practice.

"It was a really hard to move," he said. "It really felt stiff. The pain and stiffness was too much. It got the point where I had to let (the team) know."

Howard's injury comes in the middle of pivotal 10-game homestand that will go a long way toward determining whether the Phillies are legitimate playoff contenders.

"I definitely want to be out there, but at the same time I have to be smart about it," Howard said. "We have to try to nip this in the bud and hopefully I can get back out there as soon as I can."

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