The winger sustained the problem inside the first 10 minutes of last week's defeat to Crewe and will now be out of action for four to six weeks.
"The first thing we need to do is allow the swelling to subside and try to improve his range of movement," physio Ian Gallagher told the club's official website.
"He's responding well to treatment and once the movement increases we can step up his rehabilitation and begin managing his strength and general fitness.
"This is a common injury for footballers and the likely time period is four to six weeks so we'll just have to keep him progressing as quickly as we can."
