Former Arsenal midfielder Paul Merson believes Gunners new boy Thomas Partey has already proven himself to be the "number one" signing of the summer in the Premier League.
After months and months of rumours and speculation, Arsenal landed the Ghanaian international's signature on transfer deadline day in early-October, triggering the £45million release clause in his Atletico Madrid contract.
Though the 27-year-old midfield enforcer has only made four appearances for the Gunners so far, Partey has proven to be everything that Mikel Arteta - the Arsenal boss - could have wished for, with his energy and physical presence in the middle of the park not going unnoticed.
After helping Arsenal record their first away win over Manchester United in more than 14 years on Sunday, which saw a second half penalty from Pierre-Emerick Aubameyang get the job done for the Londoners, Merson has delivered an exciting verdict on Partey's start to life in north London, insisting that he has got to be the "number one" signing of the summer already.
Merson told Sky Sports: "It was a good away performance, it wasn't great, I wouldn't get carried away and say 'oh my God, it's a turning point'.
"They beat a terribly, terribly poor Manchester United team on the day. They've done a job, we've seen them lose those games over the last five or six years. But I think Partey's a massive, massive difference. I mean, what a signing.
"When you talk about signings in the summer, he's got to be number one. I cannot believe, without being horrible here, that Arsenal got him. I don't mean that in a horrible way, they're all crying out for it - I know Manchester United are top-heavy and they've got Fred, [Scott] McTominay and [Nemanja] Matic, but they haven't got a Partey."
It isn't just United that Merson believes missed a trick by not launching a move for Partey, as he believes United's cross-city rivals, Manchester City, should have also potentially considered a move for the former RCD Mallorca midfielder.
"Manchester City too, Fernandinho's coming towards the end, Rodri hasn't really pulled up any trees," Merson continued. "You're thinking 'wow, who didn't see this?'
"When you're talking about holding midfield players and you want discipline, there's no better place for discipline than Atletico Madrid. They play the ultimate disciplined way.
"They can go away and shut up shop, then other days they can go and attack teams. He's a massive part of that."
Partey's impact at the Emirates Stadium has prompted Merson to raise questions about whether or not his arrival in the Premier League should have reopened the door on Mesut Ozil's Arsenal career.
The former Real Madrid man has been frozen out of Arteta's plans and it appears almost certain that he will leave the club next season when his contract reaches its conclusion. Nevertheless, Merson believes Ozil could have linked-up nicely with the Ghana international.
"I think there was a stage for Ozil now Partey's in the team," Merson added. "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."
