Manchester United legend Bryan Robson feels that the Old Trafford club made a mistake when they let Danny Welbeck leave during the final day of the summer transfer window.
"The players Manchester United allowed to leave were all good business, apart from Danny Welbeck," Robson told talkSPORT.
"I would have kept him. He's a great lad and a good, honest player," he said.
Welbeck joined Arsenal in a reported £16m deal on transfer deadline day and could prove to be a shrewd signing on Arsene Wenger's part.
The England international, who spent his entire career at his hometown club, was allowed to leave following the arrival of Radamel Falcao from AS Monaco on a season-long loan deal.
The former Manchester United midfielder believes that Welbeck would have been a good player to have in the squad due to his commitment and is sure that the former United striker will have a great career at Arsenal.
"You would always get 100 per cent from Danny in every match. He never gets injured and would have been a good squad member," Robson explained.
"The manager has made that decision [however] and Danny will have a great career at Arsenal. He'll be playing all the time and will do well for them," the Red Devils legend continued.
Louis van Gaal and United spent over £150m during the transfer window, signing Angel di Maria, Daley Blind, Ander Herrera, Luke Shaw, Marcos Rojo and Radamel Falcao.
Robson feels with the quality they now possess, a return to the Champions League should be their aim for next season as he feels they are not yet ready to challenge the likes of Chelsea and Manchester City for the Premier League title.
"When you have the quality of players Manchester United have got now, a top four spot and Champions League football next season has to be their aim.
"I don't think they're quite ready to challenge Chelsea and Manchester City for the Premier League title though," Robson concluded.