Derby County striker Darren Bent has been sidelined for up to a month with a hamstring injury.
The 31-year-old, who is on loan from Aston Villa, suffered the problem during Saturday's 2-0 defeat at Fulham.
Bent, who joins John Eustace, Chris Martin, Zak Whitbread, George Thorne and Mason Bennett in the treatment room, is now expected to be out of action until the start of April.
Derby continue their bid for promotion to the Premier League on Tuesday when they travel to Brighton & Hove Albion.