The England striker suffered the setback in training last week, with the problem forcing him out of last weekend's 1-0 win at Sunderland.
Bent underwent a scan on Wednesday to gauge the seriousness of the injury, which relates to his right ankle - the same one he injured last season which forced him out of the final three months of the campaign and ended his hopes of being part of England's Euro 2012 squad.
Villa boss Paul Lambert said it is a case of "wait and see" but is resigned to again being without Bent for Saturday evening's home clash with Manchester United.
He said: "Darren had a scan on Wednesday and it's still too early so we will have to go with the same squad of players."
Asked how long Bent would be out, the Scot added: "Darren's doing okay at the minute but we'll have to wait and see. It is the ankle he injured against Wigan (last season) so we will wait and see."
Lambert confirmed Bent was not fit enough to even be a substitute against the Red Devils, adding: "It is not right at the moment."