Sunderland boss Gus Poyet has confirmed Patrick van Aanholt faces three months out with a dislocated shoulder.
The Dutch full-back suffered the injury in Monday's 3-1 win at Crystal Palace, and has been undergoing an assessment with the club's medical staff this week.
Poyet said: "It's bad news for Patrick, and for us.
"He's going to need an operation, so he will be out for two-and-a-half months - or possibly a little bit more."
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