The 25-year-old, who has scored twice for us this term, suffered the injury during our Sky Bet League Two clash with Southend United last week.
Manager Paul Cox revealed the news during his pre-match press conference ahead of Saturday’s trip to St Albans City in the FA Cup with Budweiser.
“Ben picked up the injury in the Southend game and it was part of the reason why we brought him off,” said our boss.
“He’s going to be a big miss, but [his absence] opens doors up for others.”
Cox continued: “We’ve had some horrendous injuries and probably a little bit of bad luck with suspensions, but I’m not going to moan or use it as an excuse.
“We’ve got players at the football club, who can come in and do a good job.”
In more positive news, our boss also revealed that both Chris Clements and Martin Riley are expected to return to training next week, whilst Ryan Tafazolli could be back in training later this week.