The Frenchman also confirmed that Bacary Sagna and Kieran Gibbs will miss out as they continue to battle problems of their own.
"Abou is an uncertainty. He has a calf problem, a minor one. It is question of days," Wenger told the club's official website.
"He will have tests and then we will see if we can use him on Sunday or not. It is a 50:50. Actually, maybe a bit more for him playing.
"(Sagna) is not ready for Sunday. It is too short for him. Kieran is not back. That was as we expected."