Leicester have failed to win a top-flight game since beating Manchester United 5-3 in a pulsating clash on September 21.
A solitary point at home to Burnley is all Pearson's side have to show for their efforts in the four matches following that game.
The manager accepts his side fell well below the required standard in last Saturday's 2-0 loss at Swansea City, but is confident his team can reverse their recent fortunes.
"The game against Swansea wasn't a good day for us, but I don't think I've said that too many times," Pearson said.
"The margins are very small, but I know we are capable of returning to winning ways against West Brom on Saturday."
Leicester captain Wes Morgan is hopeful he can feature despite picking up a knock against Swansea, but back-up goalkeeper Ben Hamer is not in the squad after dislocating his finger in training.
West Brom head into the match on the back of a disappointing 2-1 defeat at Championship side Bournemouth in the League Cup.
Head coach Alan Irvine was criticised for making 10 changes to his starting line-up in that fixture, but utility man Chris Baird insists the players must shoulder the blame and respond in the correct manner.
"Every club changes selection," he told the Express and Star. "We need games and it's the perfect chance to show what we can do.
"It's just that it didn't work out and we're very disappointed by that.
"What's important now is the Premier League and you hope playing on Tuesday night will help some of the lads be ready to step up for that when they're needed."
West Brom are winless in the last three Premier League matches, but they showed plenty of spirit to overturn a two-goal deficit to draw 2-2 with Crystal Palace last weekend.
Victor Anichebe came off the bench at half-time and impressed with a goal and winning the penalty from which Saido Berahino scored his seventh league goal of the season - only Chelsea's Diego Costa and Manchester City's Sergio Aguero have more.
Irvine is expected to revert to a similar XI that started against Palace, but he remains without Jonas Olsson (Achilles) and Claudio Yacob (personal reasons).
Silvestre Varela has resumed full training after a groin injury, but Irvine confirmed the winger is likely to be unavailable until late November.
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