Will Grigg is set to miss in-form Brentford's home game against MK Dons.
The Northern Ireland striker picked up a hamstring injury during the 3-2 Boxing Day win over Swindon - the Bees' 10th victory in 11 League One outings - and joins winger Kadeem Harris (hamstring) on the sidelines.
George Saville will be checked on after he missed out against the Robins through illness.
Fellow midfielders Toumani Diagouraga and Sam Saunders have also been struggling with the bug, but they were able to take their places in the squad and should be involved again.
MK Dons will be without the suspended Stephen Gleeson when they travel to in-form Brentford.
Gleeson received his fifth yellow card of the season during the 2-0 win at Crawley on Boxing Day and the midfielder will serve a one-match ban against the Bees, who have won 10 games in their current 11-match unbeaten streak in the league.
Leading scorer Patrick Bamford and defender Shaun Williams both came off with injuries before the end against Crawley but Dons boss Karl Robinson is hopeful the duo will be fit in time for Sunday.
He said: "Shaun's got a bit of a twinge after a knock to his back and Patrick has rolled his ankle but I can't see why they wont be okay."