Wilson revealed Saturday that he has attempted to pitch through the injury since April, saying that he had hoped to complete the 2015 season before the "eventuality" of surgery.
But after undergoing an MRI and other tests Friday, Wilson acknowledged that he likely will need to cut this season short in order to avoid a more serious long-term injury.
"I've been pushing through it for a couple months," Wilson told reporters. "I've thrown 100 innings in this condition, and it's just consistently getting worse.
"As it gets worse, the risk of blowing my shoulder out and being completely done with baseball increases, and I'm not willing to take that risk."
The Angels placed Wilson on the 15-day disabled list Friday with a diagnosis of an elbow impingement "secondary to arthritis." But Wilson offered a different diagnosis Saturday to reporters, saying that the bone spurs have reached "all four sides of my elbow" and that he now has difficulty straightening his left arm.
"There's no gray area," Wilson said. "You just run out of gas and then the tank's empty, and in this case, there's just no more elbow left to expire.
"The elbow is totally ground down at this point. I just have to get it cleaned out, rehab and I'll be fine again."
The 34-year-old Wilson said he will consult with Dr. Neal ElAttrache and Dr. James Andrews before making a final decision, although he was not optimistic that he can avoid the surgery.
"For me, it's pretty straightforward," Wilson said. "Once I get the elbow cleaned out, I'll be able to throw well again."
Wilson is 8-8 with a 3.89 ERA in 21 starts this season. His most recent outing was Tuesday, when he lasted just four innings and allowed six runs in a loss to the Houston Astros.
"There are a lot of games he pitched with a little bit of discomfort, just like any other pitcher, and went out there and got it done," Angels manager Mike Scioscia said. "But I think the last couple starts, you didn't see the crispness. You didn't see the length that he would have as far as maintaining his stuff through a higher pitch count. It was going in the wrong direction for sure."
Wilson will make $20 million next season in the final year of his five-year deal with the Angels, who have lost eight of their last nine contests and have fallen three games behind the first-place Astros in the AL West.
"The frustrating thing [is] that I couldn't get through the end of the season," Wilson said. "I knew based on the diagnosis in April that [surgery] was an eventuality, that I was going to have to get this done again. But I'm 100 innings short of where I hoped I would make it."