Former Arsenal star Paul Mariner has questioned Mesut Ozil's contribution to the club.
Manager Unai Emery has reportedly told the club to sell the German after overlooking him for selection in recent weeks.
And Mariner believes the Gunners made a mistake extending Ozil's contract last season over the likes of Alexis Sanchez and Aaron Ramsey.
"I'm dumbfounded why Arsenal would let [Alexis] Sanchez go. Sanchez, when I used to go to Arsenal to watch him play, he was phenomenal," Mariner told the ESPN FC podcast
"It didn't pan out so much for United but they let Sanchez go, they're letting [Aaron] Ramsey go for nothing! What's going on?
"And with Ozil, there's something going on with Ozil that we don't know about.
"Arsenal decided to put all their eggs in one basket with Ozil, right? But what's Ozil done for the club? Absolutely zero! Zero.
"Yes, he's a fantastic player, but he's got to get fit. He's never fit! There's something going on with this kid that we don't know about."