The Leeds United winger had an operation on Thursday afternoon and has been ruled out of Saturday’s match at Barnsley.
He is likely to be missing from action for much of January.
Simon Grayson told the club’s official website: “It wasn’t something that was planned but we were hoping to keep it quiet until after the teamsheets had been exchanged at Barnsley in order not to alert our opponents.
“We’re not putting any timescale on things but hopefully he won’t be absent for too long a period.”
Source: FOOTYMAD
