Traore, who has already agreed a four-year contract with Villa and passed a medical in Copenhagen on Tuesday, had been expected to fly to Birmingham to complete the deal on Wednesday.
However, with work permit applications currently taking longer than usual because of the coronavirus pandemic, both player and club have been forced to wait.
The 25-year-old, who knows Villa assistant coach John Terry from his time at Chelsea, has experience playing in the Champions League for the French club last season, scoring four times in 32 appearances in all competitions.