AP

Vikings center John Sullivan will spent the next three or four months rehabilitating after knee surgery.

Tom Pelissero of 1500 ESPN reports that Sullivan underwent microfracture surgery on his left knee last week.

Dr. James Andrews performed the surgery, which will likely require 3-4 months of rehab. Microfracture surgery, which creates tiny fractures in the bone, is often a last resort for players with serious knee problems, but Sullivan’s lesion was small and he is expected back before training camp.

Sullivan played every snap of the season and was only listed on the injury report as having a knee issue once, in Week 13. The 27-year-old Sullivan was on the first season of a five-year, $25 million contract in 2012.