The highly-rated 19-year-old picked up the cruciate knee ligament injury during Sunday's 2-1 win over Ipswich.
It was hoped that the injury was not too serious but tests have shown the club's worst possible fears that he has ruptured his cruciate ligament.
Commons has attracted the interest of a host of clubs with a number of dazzling displays for The Potters this season. Britannia Stadium boss Steve Cotterill was extremely disappointed at losing Commons.
"It's a major, major blow for Kris and the club," Cotterill told the Stoke Sentinel.
"My heart goes out to the lad at a time like this. It's something he simply has to get his head round.
"He started the season like a train and we know lots of clubs have been watching him.
"He's still got a fantastic future ahead of him, it's just that it's on hold for the moment.
"With modern methods he could possibly be back after six months, but I can't see me taking the risk of playing him again this season.
"He might as well wait and have an extra four months to come back fighting fit for next season."
