The Portland Timbers on Friday cleared up the intrigue surrounding offseason acquisition Jose Adolfo Valencia.

The Colombian forward will have knee surgery to repair damaged cartilage in his left knee, the team announced Friday.

"The goal is making sure (Valencia) is right," Portland coach John Spencer said.

General manager

said the surgery is scheduled for Monday. Valencia, 20, is expected to miss 6 to 12 months.

A recent MRI showed damaged cartilage in Valencia's knee. The Timbers became concerned about Valencia's knee after noticing it was swollen after a training session Jan. 23, Valencia's first day of training with the Timbers. The Timbers said no one knows exactly when Valencia sustained the injury.

"There was a small issue. Upon further investigation, (we felt) that the small issue could become a big issue," Wilkinson said. "It's better to treat it now. It's better to remove the issue to see if we can get the player to make a full recovery."

The Colombian forward had not trained with the Timbers since Jan. 24. The Timbers, saying they had to work through a variety of issues including negotiating with Valencia's former team, Santa Fe, released few details until Friday.

The new agreement with Santa Fe places Valencia on a one-year loan with a minimum contract for 2012. Valencia will go on the disabled list, but will remain with the Timbers while rehabilitating from the surgery. He will not occupy a spot on the team's roster and will not count as one of the team's international players.

"We're not rushing it," Wilkinson said. "If we did rush it, it would be selfish of us. We're trying to take care of the player. You've got to start to look at what's best for the team."

The Timbers not only had to renegotiate with Santa Fe regarding Valencia's contract, but because of the uniqueness of the injury, also had to determine the best route for treatment.

"We still think this player could be something special," Wilkinson said. "He's only 20. I think with this type of surgery, his age and the health of that particular area of his body looks very good other than this injury."

The surgery will be performed by Timbers director of medicine Dr. Jonathan E. Greenleaf at Sports Medicine Oregon.

Geoffrey C. Arnold: 503-221-8556;

garnold@oregonian.com

twitter.com/geoffreycarnold

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