Arsenal manager Arsene Wenger said he had made a decision about his future following his side's dispiriting 3-1 defeat at West Bromwich Albion on Saturday.

Wenger, Arsenal's manager since 1996, has come under heavy pressure since his team's 10-2 Champions League thrashing by Bayern Munich and fans made renewed calls for him to step down at The Hawthorns.

"I know what I'll do in my future, so you will know very soon," he told reporters after the game.

"You will see. Today I do not necessarily worry about that. We are in a unique bad patch we never had in 20 years.

"We lose game after game at the moment and that for me is much more important than my future."

Rival groups of Arsenal supporters paid for planes trailing banners that were both critical and supportive of Wenger to fly over the stadium during the game.

A banner that read "NO CONTRACT #WENGER OUT" flew above the stadium shortly before kick-off.

But in the 16th minute, with the score 1-1, another plane was spotted overhead with a banner that read: "IN ARSENE WE TRUST #RESPECTAW".

Several fans brandished "WENGER OUT" banners at the final whistle.

The 67-year-old Frenchman is believed to have been offered a new two-year contract by the club.

Arsenal's support is split over Wenger, who won seven trophies in his first nine seasons as manager but has won only two FA Cups in the 12 years since.

Craig Dawson scored twice as West Brom condemned Arsenal to a fourth defeat in five league games, which left them five points off the Champions League places.

Arsenal also lost goalkeeper Petr Cech to a muscular problem and Wenger revealed talisman Alexis Sanchez had sustained a potentially serious ankle injury.

"It's very worrying because we are not used to that. We have a hell of a task now to fight back," Wenger told Sky Sports.

"We need to improve and focus on the games coming up. There are many big games. We have to go away and recover and prepare well for the end of the season."

Cech hobbled off shortly before halftime, with David Ospina taking his place, while Sanchez gave way for Alex Iwobi late on.

"We lost Petr Cech in the first half on a calf problem and after we lost Sanchez," Wenger said.

"He stayed on, but in the second half he was not himself so I decided to take him off. His ankle doesn't look good. When it doesn't go well, it's always the same."

Former Arsenal striker Thierry Henry delivered a damning verdict on the team's performance.

"They were nowhere near the desire and the commitment needed to win a game in the Premier League," he said.

Arsenal midfielder Alex Oxlade-Chamberlain apologised to the club's fans after the game, describing their performance as "not acceptable".