Mikel Arteta "missed a trick" by cutting Mesut Ozil from his squad now he has Thomas Partey in the team.
The Ghana international signed for Arsenal on deadline day from Atletico Madrid and could turn out to be his most important player.
It could be argued that Partey is the first proper defensive midfielder in years to join the Gunners.
But it is not just his work-rate and ability to break up play that has caught the eye.
The 27-year-old has also showed his remarkable playmaking abilities by dinking some exquisite balls.
And Paul Merson reckons Arteta has made a mistake by not including Ozil in either his Premier League or Europa League squads.
The German has been lambasted for his lack of effort at times but with Partey behind him, he would not have to worry about his defensive work, Merson argues.
"I think there was a stage for Ozil now Partey's in the team," he said.
"I watched Chelsea play against Burnley, they played a back four, they played N'Golo Kante in front of the back four, and let everyone else get on with it.
"They ripped Burnley to shreds, I haven't seen too many teams make Burnley look bang average.
"Because Kante was playing in that holding role, it gave Kai Havertz and Mason Mount the freedom to do what they want.
"They didn't have to spend most of their time on the edge of their own box tracking back.
"With Partey in there now who's so dominant in there and doesn't lose the ball, I think there was a place for Ozil now. I think there was.
"Then if they do drop someone in to pick up Ozil, you've got someone like Partey who's very comfortable on the ball and can hurt you.
"Then that frees a midfield player up. I think there's a trick being missed here, but that's just me.
"He's that good I think it would've opened up a space for Ozil.
"But he's not for one reason, and that's because he doesn't run around.
"Why did Manchester United get beaten on Sunday? Because they don't run around."