While Manchester United have made a mess of midfield signings over the years, Arsenal have mastered their transfer strategy.

And that's become even more evident this season, with Martin Zubimendi quietly staking a claim for signing of the season after another Mikel Arteta masterstroke.

For United, though, Casemiro is a shining example of their flaws, and the Brazilian will bring an end to his unsuccessful stint in the Premier League at the end of the campaign.

The No.6 role, initially with Thomas Partey, and now Zubimendi, has been an integral reason behind the Gunners' rise up the table.

It took more than a decade, but Arteta recognised that the engine room of Arsenal's golden-era midfield, Patrick Vieira and Gilberto Silva, was never replaced.

Partey was one of Arteta's first permanent signings, with Jorginho coming in soon after. Zubimendi, however, has taken the role to another level for the Gunners, while the Arsenal boss has done the same with the former Real Sociedad talisman.

Alvaro Romeo, the Spanish editor for The Coaches' Voice, detailed both why Arsenal decided to sign the Spaniard and where he has since improved under Mikel Arteta.

"He has improved a lot over the last two years....