Brentford are set to be without DR Congo forward Yoane Wissa for "a couple of months" with an ankle injury, the Premier League club's manager Thomas Frank said Monday.

Wissa, 28 opened the scoring inside 30 seconds against champions Manchester City on Saturday, but was then substituted just before half-time following a challenge with Mateo Kovacic in a match the Bees eventually lost 2-1.

Frank, speaking ahead of Tuesday's League Cup tie against fellow London side Leyton Orient, told reporters: "Wissa is not good news. It looks like an injury that will be a couple of months. 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 pre-season signing Igor Thiago because of a knee injury, while England striker Ivan Toney has left for Saudi Pro League club Al-Ahli.