Ghana midfielder Partey joined Mikel Arteta’s Arsenal on transfer deadline day after the Gunners met his £45million release clause.
Despite Arsenal losing two of their last three games, Partey has enjoyed a promising start to his career at the Emirates, with Arteta describing his debut as ‘fantastic’.
And former Liverpool and England winger Barnes reckons Manchester United ‘could have done’ with a player like Partey to protect the team’s leaky defence.
Ole Gunnar Solskjaer instead made Donny van de Beek one of his marquee summer signings but the Dutch midfielder is struggling for game-time at Old Trafford.
Barnes told Bonus Code Bets: ‘People assume that if you come from Ajax and cost £40m, then you are going to get a player like Johan Cruyff but it’s never going to happen.
‘He [Van de Beek] will be a good player for United eventually, but they have to get the balance right in how they want to play and where he fits into that.
‘Currently, Manchester United want to play pretty football by having lots of flair players, which he doesn’t fit into so now he is getting criticised by fans and pundits because that is not the way he plays.
‘At a team like United where everyone is so inconsistent, you are going to get judged when you aren’t a flair player.
Barnes added: ‘Manchester United are in need of a midfielder who will sit in front of the defence and protect them.
‘United are at the stage now where they believe that they need players who, like Paul Pogba and Bruno Fernandes, are great on the ball and very attack-minded.
‘However, with the way things are portrayed now, for £40m, if you aren’t doing something that is eye-catching, then you are considered a waste of money.
‘Donny van de Beek is not a flair player like Pogba or Fernandes and can’t get people off their seats in the same way.
‘Manchester United have conceded lots of goals already this season and could have done with a player like Thomas Partey. He would have made them much more defensively sound.’