By SABC Sport
17th September 2024
Wissa opened the scoring inside opening 30 seconds against Manchester City on Saturday, but was then substituted just before half-time following a challenge with Mateo Kovacic.
Speaking ahead of Tuesday's Carabao Cup tie against Leyton Orient, Frank confirmed Wissa was set for a spell on the sidelines.
"Wissa is not good news. It looks like an injury that will be a couple of months," Frank said at a press conference.
"It is very frustrating. It will leave a hole, but I will find a solution and other players will step up."
Brentford are already without summer signing Igor Thiago, who has a knee problem, while England striker Ivan Toney left for Saudi Pro League club Al-Ahli ahead of the transfer deadline.
Frank added: "It will leave a big hole. Everybody was saying we bought Igor Thiago to replace Ivan (Toney) - but we still had Wissa.
"We bought Igor Thiago to build the squad and provide competition in the squad.
"Wissa had a very good season last year and I thought he has started the season very well this year, with three goals in four games, that's a very good number.
"He's just been very important for us and that's going to leave a hole. But, again, I will find a solution."
Brentford won 1-0 at Colchester in the last round and Frank has his sights on an extended cup run.
"It is a a competition we take very seriously. I think we have said that for quite a few years," the Bees boss said.
"We want to go on a cup run, to do our best to see how far we can go and that will be the same tomorrow.
"We have big respect for Leyton Orient, we know it will be very difficult.
"We know we can lose - just like we did to Gillingham (on penalties in November 2022) - but that is part of football."
Should the Bees progress in the competition, Frank would like the semi-finals to be one-off ties rather than two-legged affairs.
"We want smaller clubs to go on a fairytale run and we would like to do that," the Brentford boss said.
"But we know if we are facing (Man) City, Man United or Tottenham over two legs, then that means we have less of a chance to beat them.
"So there is no reason, or no good argument why we should have two semi-finals.
"I know it always come down to finances, but there must be some sensible persons that can go into a room and find a good way to solve it and I am happy to facilitate the meeting."