MORE: Alex Morgan upset at 159-degree temps | Transfer photos
Wenger has claimed that he will not be rushed to sign a new striker following Olivier Giroud's injury, but admitted he could still strengthen any area of the team.
"We are open for any position as long as we feel that the player can strengthen the squad," he told reporters after Wednesday's 1-0 win against Besiktas.
"Buy to buy, I don't see the purpose of that. If we find the players who we feel can give something to our squad, we will do it in any position. We are open but it has to be enough to buy. It has to make sense."
Arsenal is expected to step up its recruitment efforts in the coming days after securing a place in this season's Champions League, and with it an estimated 38 million euros in income.
The Gunners had previously been interested in Real Madrid midfielder Sami Khedira, but were put off by his wage demands before the Germany international elected to stay in Spain.
Manolas electing to join Roma will also have come as a blow to Wenger, who is looking for reinforcements at the center of defense, with just 19-year-old Calum Chambers currently providing cover for Per Mertesacker and Laurent Koscielny.