Traore was injured in the 3-1 defeat by Sunderland last week -- a result that left the Midlands club marooned at the foot of the Premier League, 11 points adrift of safety.
Villa's website said Spaniard Traore, signed from Barcelona last year, had broken a bone in his foot.
"It is a big blow," manager Remi Garde said. "He is a nice weapon to have but he's going to be out for quite a while."
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Traore's absence underlines Villa's need for urgent reinforcements in the transfer window.
"The group has been suffering for a long time now, since the beginning of the season," Garde, who hopes to get his first win as Villa manager in this weekend's FA Cup tie against fourth-tier Wycombe Wanderers, told a news conference.
"We need fresh players to regenerate this group. Sometimes the spark needs to come from outside. Hopefully this is what will happen in the transfer window."
Attracting players to a club that looks destined to drop out of the Premier League could be difficult though.
"If I can attract the first one, maybe the others will follow," former Arsenal midfielder Garde, who took over from sacked Tim Sherwood in November, said.
One player Garde hopes to sign on loan this month is Arsenal right back Mathieu Debuchy, confirming on Thursday that he had spoken to Arsenal manager Arsene Wenger about a possible deal.
(Reporting by Martyn Herman; editing by Amlan Chakraborty)
