The former England full-back has been playing through the pain in recent weeks but has now gone under the knife to cure the problem.
Manager Nigel Adkins told the club website: "It's a big blow.
"He's a talented, talented player. He's been really good, we were really excited to get him in the summer.
"We've been managing him for the past few weeks but he'll be out for a few more weeks now, we just needed to tidy things up a bit."