Wilson said he felt something on a bases-loaded, one-out pitch to Todd Helton in Coors Field on Thursday. Helton lined out to second baseman Emmanuel Burriss. Wilson then delivered two balls to Tyler Colvin before walking off the mound.
"He looked like he slipped on a pitch," Bochy said. "It was not the norm and that's why I visited the mound. I asked him if he was OK and he said he stepped in a hole and tweaked his ankle and just needed to walk it off. He threw a couple of pitches and said he was fine."
He was far from fine though, walking in a run and prompting another mound visit before getting Marco Scutaro to fly out to end the game and record the save, which will probably be the only one he gets all year.
"You can tell what pitch didn't work well," Wilson said. "I thought if my season ended, I wanted the last pitch to preserve Madison Bumgarner's win. I was not going to walk off the mound a failure."
Wilson underwent a similiar surgery while pitching for LSU in 2003 and understands the long rehab process.
"If it takes a year, no big deal," he said. "If I'm going to pitch forever, this will be a small percentage of my career. The first time it happened, I was a 21-year-old kid who was going to get the opportunity to throw harder."
Wilson plans to visit several more doctors during the week and will probably reach a decision by next weekend. He sounds like the decision has already been made.
"Giants fans may look at it as a big loss, but we have the best bullpen in the league and we're going to take the [National League] West whether I am here or not," said Wilson. "The first thing I did was download the MLB app for my iPad. I've got 150 or so games to watch."
Wilson said he "was pitching on borrowed time" all of 2011 and admitted the stress on his arm could be associated with the 2010 march to the World Series title.
"That's the way I pitch, though," he said. "I would not have pitched any other way. I'm not worried about coming back. I'm most disappointed knowing what a grueling process it is I'm going to have to go through again. I've never shied away from hard work, but it is more of a mental anguish, the monotony of the daily exercise."
Wilson expects to remain with the team while he rehabs, but Bochy thinks there will be a different scenario.
"The most important role for him is how vital it is to be consistent with his rehab," said the manager. "He needs to put in the hours to get healthy. I know he wants to be here but we may not see him for a while, at least the early part."
Wilson said he'll benefit from remaining with the team because of the support he receives from "my 24 best friends out there and the coaching staff. I have an entire city that is my friend."