For the second time in less than two years, Ryan Howard will require surgery on his left leg. The $125 million Phillies first baseman tore a meniscus in his left knee. He will miss 6 to 8 weeks from the date of his surgery, which has yet to be determined.

His season could be in peril, depending on how quickly he can recover and whether the Phillies are still in contention come September.

"We can only speculate the length of how long it will take to get him to rehab," Phillies general manager Ruben Amaro Jr. said. "We'll shoot for the conservative one and hope he comes back faster."

Amaro compared Howard's injury to that of Erik Kratz's, who began a rehab assignment with triple-A Lehigh Valley on Monday. Kratz underwent surgery June 12 and could return by this weekend. He is well ahead of schedule.

But Howard has a history of troubles in his left leg. Surgery was needed to repair a ruptured Achilles tendon in October 2011. He has recently complained of left foot problems, although Amaro said he was totally unaware of such issues.

Howard first appeared on the team's internal medical report sometime around May 4. He received a cortisone injection May 19. Phillies head athletic trainer Scott Sheridan said inflammation revealed in an MRI "concerned us." Howard returned to action May 21 before succumbing July 6.

The timeline is eerily similar to when Howard tore his Achilles. He was injected with cortisone Sept. 18, 2011. He collapsed on the field Oct. 7. Major surgery followed.

This injury is far less serious. Amaro said that original MRI in May showed "fraying" of the meniscus, but not a tear. That happened while playing on the bad knee.

"We have to take care of it," Amaro said.

Not every recovery is as smooth as Kratz's. Cincinnati first baseman Joey Votto injured his knee in late June last season, attempted to play on it for two weeks, and then opted for surgery to repair the torn meniscus. Votto missed the next 10 weeks.

Howard is under contract through 2016. He has played in 151 games since the Achilles injury and hit 25 home runs with a .244 batting average and .752 OPS.

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