The striker, who currently plays for MLS side New York Red Bulls, recently claimed that he would "love" to make a comeback at the Emirates in the future.
"As a player it will be difficult," talkSPORT quotes Wenger as saying. "Any other function why not. He has to decide what he wants to do."
The 35-year-old, who spent a loan stint at the club, scored 226 goals during his eight-year career with the Gunners.