West Brom right-back Steven Reid will be sidelined for a month after undergoing a successful knee operation.
The 30-year-old twisted his knee in Wednesday's win at Newcastle, but the operation was to repair wear and tear suffered in recent months.
The Baggies are hoping the ex-Blackburn man recovers from the injury suffered at St James' Park while he recuperates from surgery.
Reid, who was replaced by Billy Jones in the 3-2 midweek success, had been a Premier League ever-present this season.
"Steven Reid will be sidelined for around a month after undergoing a successful knee operation," read a statement on the club's official website.
"The right-back required the surgery to repair wear and tear that had built up over the past couple of months.
"He was forced off in the seventh minute at Newcastle on Wednesday after twisting his left ankle and it is hoped that this injury will also heal during his rehab from his left-knee operation."
West Brom will continue to monitor James Morrison's hamstring injury and Youssouf Mulumbu's groin injury ahead of their Boxing Day clash with Premier League leaders Manchester City.