Reports emerged earlier today that the Gunners were closing in on a deal for the Greek centre-back.
The 20-year-old only made his professional debut in November 2016 but he has been coveted by some of Europe’s biggest sides.
But it looks as the Arsenal have beaten their rivals to his signature with Wenger confirming the deal after his side’s 2-2 draw with Chelsea.
However, Wenger on to say the defender will be sent out on loan with reports suggesting he could join Werder Breman.
“Yes, but he’s not ready to play or run,” Wenger said.
“He will go out on loan.”
While Mavropanos is seen as one for the future, Arsenal are expected to be busy in the January transfer window with Alexis Sanchez and Mesut Ozil facing uncertain futures at the club.
And Wenger stated his intentions yesterday to bring in more players to the Emirates.
“When is difficult to say. We look of course to do something,” he said.
“We will do, but I can’t say when. We are open in any position for an exceptional player.
“It depends on injuries as well and who we manage to extend the players’ contracts who are up in June.”