West Brom midfielder Steven Reid has been ruled out for one month following a knee operation.
The 30-year-old required the surgery to "repair wear and tear" but it was not related to the ankle injury he suffered in Wednesday's 3-2 win at Newcastle.
A club statement confirmed: "He will be sidelined for around one month.
"He was forced off at Newcastle after twisting his left ankle and it is hoped that this injury will also heal during rehab from his left-knee operation."
Reid has also played at right-back for the Baggies this season.
Meanwhile, West Brom boss Roy Hodgson will assess the fitness of James Morrison and Youssouf Mulumbu ahead of the Boxing Day clash with Manchester City at The Hawthorns.