Arsenal defender Shkodran Mustafi said the club and the players were not able to "assist" Mesut Ozil when he "needed us the most" in a glowing tribute to the departing playmaker.
Mustafi has long been one of Ozil's closest allies in the dressing-room and he has described his friend as the most "unselfish" player he has ever played with.
Ozil is in the process of finalising his transfer to Fenerbahce as a free agent after reaching an agreement with Arsenal over the termination of his contract.
It follows the loan departure of Sead Kolasinac, the other key member of Ozil's friendship network at the club, and Mustafi could be the next to leave as he has only six months remaining on his current deal.
In a post on social media, Mustafi said: "Bro, you have been the most unselfish player on and off the pitch, I have ever shared the dressing-room with. You will always be remembered as the #AssistKing."
Meanwhile, former Arsenal midfielder Jack Wilshere has rejoined Bournemouth on a short-term contract.
Wilshere previously spent the 2016/'17 season on loan at Bournemouth and the midfielder is hoping that the move to England's south coast can kick-start his career after he left West Ham as a free agent in October.