The Rays say they are optimistic Howell will make a full recovery and be ready for the start of the 2011 season.
"We certainly knew that [surgery] was a possibility," said Rays executive vice president of baseball operations Andrew Friedman. "We went through the rehab process in a very methodical way to give us the best chance to get him back on the mound. And it didn't work.
"In the meantime, we strengthened up the shoulder in that process, which we feel will aid in that recovery. And from all indications, today went really well."
Howell, who has been recovering from a weak shoulder since Spring Training, began throwing a simulated game Monday afternoon, but after throwing 12 pitches, he left the mound and looked visibly upset. The left-hander then traveled to Birmingham, Ala., on Tuesday to visit with Rays medical director Dr. James Andrews, who performed the surgery Wednesday.
"Obviously he was frustrated," said Friedman, who talked to Howell prior to the surgery. "It was an emotional moment for him, going through this for the first time. He's in great hands. He's got a great work ethic and is a great competitor. I certainly wouldn't bet against him. And we're optimistic that we'll get him back and he'll be the J.P. Howell of old."
Howell went 7-5 with a 2.84 ERA and 17 saves in 2009 while being used primarily as the team's closer. The Rays had expected Howell to be back with the team by late May, and they were hoping he would be able to set up new closer Rafael Soriano this season.
Rays manager Joe Maddon characterized Howell's surgery as "bad news in a sense."
"But the good news is he's going to be well," Maddon said. "It's something where we tried everything to avoid it, but it was unavoidable as it turned out. We've just got to get him through this moment -- the operation, the rehab -- and get him back to the group.
"He's going to be a significant part of our future, I believe. It's tough for anybody, but this guy has such exuberance for the game of life in general. He's a big part of our soul and spirit around here. The guy's going to be missed. But he's going to be back at some point, and we're thankful for that."
Friedman said it's unlikely the Rays will be able to have a timeline for his recovery until the offseason.
"But the fact that we're optimistic that he'll be able to start [next] season means that at some time in January, he starts a throwing program," Friedman said. "As far as undergoing shoulder surgery, it went as well as could be expected."
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.