The Baggies are preparing to take on Southampton this weekend but will be without the Northern Ireland midfielder who will continue to be monitored during the season run-in says manager Steve Clarke.
"Chris' injury is a little bit of a concern for us,” he said.
"It would be nice to think he'll only miss one game but there is a possibility he will miss more than one game.
"He's not going to make it this week and it is fingers crossed for next week. Hopefully the medical department will do the job they've done all season and get him back quickly."