The Baggies travel to north London on the back of two straight defeats but still sit fifth in the Premier League table, while the Gunners lie in 10th place.
But Clarke expects Arsenal to be determined to get back to form after enduring their worst start to a season for 18 years and is preparing his side for a backlash.
"It's a game that we have to be positive about and look forward to," he told reporters.
|THE BACKLASH TO THE BACKLASH?|
|12/1||Arsenal are 12/1 with PaddyPower to have a half-time lead but fail to beat West Brom|
"Arsenal are probably not playing as well as they would like and they've had some reverses so they'll be fired up to try to turn their season around."
Wenger has come under intense scrutiny in recent weeks, with the Arsenal fans showing their dissatisfaction after their 2-0 defeat at home to Swansea City.
"The way the game is now means, no matter what club you're at, if your team is not doing well you're going to get criticism," Clarke added. "That's the state of play with Arsenal at the moment.
"The team hasn't been firing as maybe people thought they would do, especially after the start they had.
"They've introduced a few new players this year and it's maybe just taken the team a little bit longer to find a rhythm than it did before but nobody can question the record of Mr Wenger. It's a great record, he has done fantastically for the football club and I'm sure the club will stick with him."