The 29-year-old underwent scans that revealed ligament damage, although it is not yet known whether or not he will need an operation.
Manager Justin Edinburgh told the BBC: "It's a real bad one. It looks like he's severely damaged ankle ligaments.
"He may need an operation but he's going to be out for a minimum of 12 weeks.
"That's just about how our luck's gone this season with injuries. I don't go on too much about it but we've had an horrendous time of it.
"But we've dealt with it as a squad and a club very well. Credit to the players but it's a big blow for us."