Powell has been nursing a hamstring injury for several weeks but the midfielder may come into consideration for a place on the bench at Griffin Park.
A hamstring problem has seen on-loan forward Patrick Bamford return to parent club Chelsea for treatment and the teenager will continue to be monitored.
Dean Lewington is another player to have a hamstring twinge recently but the captain came through the full 90 minutes against AFC Wimbledon on Sunday and he is expected to continue at left-back.
Ryan Lowe started the FA Cup second-round victory against Wimbledon but he faces a battle with Alan Smith and former Brentford striker Charlie MacDonald for a place in the starting XI.
- Sports & Recreation
- Patrick Bamford
- Dean Lewington