The heavyweight star recently underwent surgery to address neck, back and nerve problems, and will not be allowed any physical contact for 8-12 weeks, his manager Jason Genet told MMA Fighting.
The procedure, performed on Nov. 2 by neurosurgeon Dr. Chad Prusmack in Colorado, took four hours and required drilling into Carwin's skull as part of the process that repaired nerve damage and problems with his C5, C6 and C7 discs.
"It went as good as it could have, but it was worse than we thought it was, if that makes sense," said Genet, who explained that the extent of the problem wasn't completely known until Carwin went under the knife.
The 35-year-old Carwin (12-1), a former collegiate wrestling champion and NFL prospect before transitioning into MMA, had been suffering through the injuries for years, working through them with physical therapy, traction, pain pills and epidurals.
Recently, the injury had resulted in more pain and eventually, numbness in his fingers and one of his arms. By the time surgery was nearing, the problem had progressed to the point Carwin had trouble sleeping and would vomit from medication.
"His body was out of whack and it could have caused some severe damage if it had not been addressed," Genet said. "It was very much required.
"When he woke up, the pain in his back where knife-pain was in the last few weeks was gone, he could feel his fingers, and the numbness was gone," he continued.
In one to two weeks, Carwin will be able to begin light cardiovascular or mobility workouts, but can't do any impact training or weight lifting for the foreseeable future.
Given the 8-12 week no-contact timeframe and a traditional 6-8 week training camp, it seems likely that Carwin won't be back fighting in a UFC Octagon anytime before spring 2011. But the best news Carwin received is that his fight career should resume with no restrictions once he is fully rehabilitated.
"Their doctor said he was surprised Shane could compete with the damage as it was, but with the surgery, there's no reason he won't be able to fight and possibly even perform at a higher level," Genet said. "Once Shane gets back into the motions, we think it'll be relatively quick for him to get into fighting shape. He's not a guy who has a lot of ring rust."
Carwin was most recently in action at UFC 116, where he nearly took the UFC heavyweight title from Brock Lesnar during a one-sided first-round before he succumbed to a second-round arm triangle submission. A power puncher with a wrestling background, Carwin had finished all 12 of his opponents prior to losing to Lesnar, and captured the UFC interim heavyweight championship with a knockout over Frank Mir at UFC 111.