The Spanish defender will be asked to slot in at wing-back for the trip to the bet365 Stadium due to the likely absence of Oxlade-Chamberlain, who damaged his hamstring in the 2-0 win over Southampton on Wednesday night.
Bellerin has struggled for form and was taken out of the firing line by Wenger last month after being jeered by his own supporters at Selhurst Park, but the Frenchman believes that his new 3-4-2-1 formation will get the best out of the 22-year-old.
"Yes he is [a natural replacement], he is an offensive player," Wenger told reporters. "He started as a right midfielder and we transformed him into a full-back.
"He's a player who has a fantastic mentality. He went through a difficult period when he came back from his ankle injury, but I never questioned his attitude. He has great spirit."
Oxlade-Chamberlain is to undergo further tests on his damaged hamstring on Friday, but the injury is not expected to rule him out for the rest of the season.