Mesut Ozil appeared to mock former Arsenal boss Unai Emery in a tweet prior to the Gunners' Europa League semi-final second leg against Villarreal at the Emirates.
Emery, now in charge of the Yellow Submarine, led his side to a 2-1 win in the first leg in Spain as both sides bid to reach the final, likely against Manchester United.
Ozil fell out of favour under Emery in north London before being exiled altogether by current boss Mikel Arteta, leading to a move to Fenerbahce.
But the German left Arsenal fans under no illusions which side he was on ahead of the clash between his two former bosses.
He tweeted: "Good ebening, Gunners! I hope my former teammates will turn this game around tonight - let's go!"
Emery was roundly mocked for his difficulty in saying "evening" when speaking to TV cameras during his time at Arsenal, something seemingly referenced by Ozil in his tweet.
Arsenal need to win the Europa League to have any chance of playing in the Champions League next season, having fallen out of top-four contention during a sub-par Premier League campaign.
And Gunners legend Martin Keown believes the return of Kieran Tierney provides a boost.
“Tierney is a wonderful player," he told BT Sport. "I’ve talked about, maybe in the future, him becoming captain. He’s a driving force, he gets down that left hand side time after time whipping crosses in."
The Scotland international was due to start on the bench, but an injury in the warm-up to Granit Xhaka saw him drafted into the starting XI.
Before that news became apparent, Keown added: “It’s great news that he is there on the bench. Let’s hope the team can do the job in front of him, without him coming on and having to be necessary tonight. He is there if they need him."
