The forward is out for a few weeks with a bad ankle injury, suffering the problem in a 2-1 loss to Brighton on Wednesday.
As the Bees look to bring back Ivan Toney into their team in mid-January, Mbeumo will be hoping he is at AFCON by then.
He is hoping to represent Cameroon at the tournament, which begins January 13th.
Manager Thomas Frank said on Thursday: “He rolled his ankle. It is bad — I don't know how bad.
“We don't have the exact number of weeks. He will definitely be out for Saturday [away at Sheffield United] and for weeks."
On replacing Mbeumo, Frank added: “Yes, but it was also hard to replace Ivan [Toney].
“We normally find a way. That's football and it happens sometimes. We will find a solution. There are other players who can step up.
“We need to do everything we can to recover well, and there is also some bad luck in it. [An injury for] Bryan is just bad luck. He gets caught and rolls his ankle. Very frustrating, of course, but I am a positive guy.
“Football is such a marginal game. Hit the post, inside the post, outside the post, deflection: there are so many things you can't control, like injuries."