General manager Tony Reagins announced before Friday's game that Escobar and his agent, Peter Greenberg, agreed that the pitcher needed surgery after his shoulder couldn't respond to previous rehab attempts.
The operation will be performed by orthopedist David Altchek sometime before the end of July. Reagins said the recovery time, judging by comparisons to other players who've had similar injuries, is "a significant time," likely "nine months to a year."
Escobar initially reported shoulder pain last September and again in preparation for Spring Training this season. An MRI in February showed no significant injuries and the Angels initially believed Escobar would return sometime before the All-Star break.
But another MRI in March revealed the torn labrum. He continued rehabbing the injury and felt healthy enough to throw a flat-ground session on July 4. After about 10 pitches, though, the pain flared up again.
"You can never get too high or too low," Reagins said. "You hope for the best, but you know there's going to be a setback along the way."
He was examined last week by Altchek and orthopedist Lewis Yocum and their findings led to the decision for surgery.
"They both agreed as to the extent of the injury," Reagins said. "They're going to go in there, make the necessary repairs. Just as a matter of practice, surgery is the last option, and that's where we are."
"I think we all saw how hard Kelvim worked through spring," manager Mike Scioscia said. "I think we all felt there was no question he was going to pitch for us in some capacity this year."
Despite the news, Reagins insisted there will be no push to add pitching depth before the July 31 trade deadline. Angels pitchers have thrived without him (a combined 3.82 ERA) and the club currently leads the American League West by five games.
Would it have been nice to have that added boost, though?
"Big if," Reagins said. "Shoulda, coulda, woulda. We operate like that, then we're in trouble."
Escobar and the Angels training staff now will focus on getting the pitcher healthy for action next year. If the surgery and subsequent rehab goes well, he could be healthy toward the beginning of the 2009 season.
"We'll wait for the direction that the doctors give us," Scioscia said. "It's obviously significant if you have to go in their and operate."
David Biderman is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.