West Brom's Olsson ruled out until new year

The Swede has only featured five times for Alan Irvine's men in all competitions this term and is set to undergo the procedure in Portugal on Friday.

West Brom have estimated Olsson's recovery will take four to six weeks, but the 31-year-old believes action needed to be taken.

"I have been struggling with this on and off for some time and I've come to the point where it feels like surgery would help it," he told the club's official website.

"The recovery time is short, so I hope to be back 100 per cent some time after the New Year."

Meanwhile, Sebastien Pocognoli has returned to training following a hamstring problem.