Dean Smith admitted the decision to omit Lewis Macleod was a tactical one and the Scot hasn't suffered an injury.
The midfielder, who has been absent for a year after a knee injury, has been in recent squads but was omitted, sparking concern amongst Brentford fans about his fitness.
Macleod has been beset by injuries since moving to Griffin Park in 2015 and it caused him to play just seven minutes in his first 18 months with the club.
However, Smith explained that he wanted Ilias Chatzitheodoridis on the bench to cover for Yoann Barbet, given his inexperience at left back.
The head coach said: “It was tactical. Yoann isn't used to playing left back and I felt I needed Ilias on the bench in case he tired.”
Macleod will hope to be earning a place in the squad and starting XI against QPR with the Bees producing a poor performance against Burton as they were held to a 1-1 draw.