Villa's ?18million record signing sustained the latest setback in training on Friday and was ruled out of the weekend 1-0 win at his former club Sunderland.
Bent has been replaced in the starting line-up by Christian Benteke in recent weeks but another lengthy spell out of action would still be a blow to the midlands club.
Villa boss Paul Lambert said: "Darren hurt his ankle on Friday in training.
"It is the same ankle he hurt against Wigan (in February). I know it was serious then.
"Is it serious? I don't know yet. He will get treatment on it during the week and we will see.
"He was really hobbling on Friday and we couldn't take a chance on him with Sunderland."
Bent suffered last season's ankle problem against Wigan in late February and it ended his hopes of being part of England's Euro 2012 squad.
The form of Benteke and Gabriel Agbonlahor, who have scored five goals between them in the last three games, has meant he has been had to be content with a substitute's role in recent weeks.