The £18million striker has been ruled out for four weeks with a hamstring injury, says The Sun.
Boss Paul Lambert confirmed: "Darren went for a scan on Wednesday and it's looking like he'll miss the Christmas games. It's a blow for him."
Bent, 28, will now also lose the chance to battle his way back into Lambert's plans after making a rare start in Tuesday's League Cup win against Norwich City.
When he returns the transfer window will be open and, with other clubs interested, it could be curtains for Bent.