Scott Malone is set to miss the remainder of the Championship season – unless Millwall reach the play-offs.
The left wing-back came off in Monday’s 2-1 win over Hull City with a hamstring injury.
And a scan earlier this week revealed that Malone will be out for between four to six weeks.
The Championship play-off final is on May 29 which is around the earliest that the former Fulham, Huddersfield Town and Derby County defender could be back in action.
Malone will miss today’s match at Birmingham City. If the Lions win they could move into the top six.
The most likely scenario is that Murray Wallace will shift to left wing-back with Shaun Hutchinson replacing the Scot in the middle of the back three.