West Brom dealt defensive blow ahead of Portsmouth trip
Albion defender Krystian Bielik has been ruled out for up to a month after a shoulder injury.
Experienced defender Bielik, 28, has captained the side in recent weeks but is sidelined for three to four weeks with the dislocation from last week's draw at Derby.
Eric Ramsay's Baggies play seven fixtures between Saturday's crunch trip to Portsmouth and the end of February.
Pole Bielik, a recruit from Birmingham City last summer, has only recently returned from an ankle setback that sidelined him over the Christmas and New Year period.
It is the Baggies' second injury blow this week ahead of the trip to Fratton Park, as attacker Karlan Grant was ruled out for three months due to surgery on a hamstring injury from Derby.
Bielik has played 14 games in an injury-hit debut campaign at The Hawthorns, and it took until October 1 at Norwich - Albion's last away league win - for him to make his debut.
