Former Maryland corner back J.C. Jackson underwent an uncommon surgery over the offseason, which leaves him questionable in Week 2.

Jackson underwent surgery to remove an extra bone in his ankle, Ian Rapoport reported Thursday. He was born with extra bone in the back of his ankle.

An extra bone is rare but not unheard of. While most people don’t notice the extra bone, Jackson started to experience serious pain from it, which is why he decided to have it removed per Rapoport.

The surgery, which is just taking the bone out, is not considered major surgery and leaves Jackson out for just 2-4 weeks.

Jackson, who joined the Chargers over the offseason, has 158 tackles and 25 interceptions on his career. Jackson played just one season at Maryland in 2016 before declaring for the NFL Draft.