One will be enforced with winger Ben Marshall set for a spell on the sidelines after suffering a foot injury during the Championship defeat at Peterborough on Saturday.
"Ben has had an x-ray so we've ruled out a break," Pearson told reporters. "We'll just have to see how he recovers over the next few days.
"He sustained it just after he scored. He had a chance at the far post, went to shoot and I think he kicked the defender's foot. It was a bit of a concern but he's a bit sore at the moment and we're not quite sure when he'll be available."
The likes of midfielders Lloyd Dyer, Matty James, Paul Gallagher and Richie Wellens and strikers Martyn Waghorn and Marko Futacs - all of whom were on the bench against Posh - will come into contention for recalls.
In-form striker Chris Wood missed out at London Road with a knee injury. The Kiwi will remain absent against the Terriers, against whom he scored twice on New Year's Day as Leicester romped to a 6-1 league win, but he is expected to be fit for the Foxes' next Championship game against Charlton on February 19.
"He has a knock on his knee. It's not something we're too concerned about but he won't be considered for Tuesday," said Pearson.
"Hopefully he will be available for the next league game, and that's what we're looking at."
The City boss added: "We don't have a big squad in which you've got a lot of fringe players; we've got a tight squad of good players. I'll be looking to freshen it up where I need to but essentially we're looking to get the side right so we can win the game."
The winners will host Wigan in the fifth round on Sunday.
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