Former England manager Fabio Capello believes Roma's Daniele de Rossi should have joined Manchester United this summer, also revealing David Moyes contacted him for his opinion on the midfielder.
The Premier League champions desperately sought to add to their midfield options this summer as they pursued Thiago Alcantara, Cesc Fabregas and Anders Herrera to no avail before eventually signing Marouane Fellaini minutes before the transfer deadline.
Italy international De Rossi was reportedly subject of an opening bid of £12m in August, an offer that was swiftly rejected by the club who saw little reason to listen to offers for their talismanic midfielder.
But Capello, who managed Roma as De Rossi was finding his way out of the youth ranks and into the heart of midfield, believes the 30-year-old has made a mistake in not pushing for a move to Old Trafford, also revealing United boss Moyes contacted him for his opinion on the player during the summer.
"Had I been in the shoes of De Rossi then I would have joined Manchester United," Capello, the current Russia head coach, told Fox Sport.
"I would have wanted to go to a club where the ambition is very high.
"A few months ago David Moyes asked me for an opinion of the player, an opinion which was positive."
United's repeated attempts to bolster their midfield came under increased scrutiny as they persistently failed in their offers for potential targets.
The club lodged two official bids of £25m and £30m for former Arsenal captain Fabregas despite claims from the player earlier in the summer he had no intention of leaving Cataluña again.
United's pursuit only came to an end when Barcelona coach Gerardo Martino announced upon his unveiling that he expected the midfielder to stay.
United would turn their attention to Athletic Bilbao midfielder Ander Herrera on transfer deadline day. But after a confusing saga it would eventually transpire that Moyes was unwilling to match the 24-year-old's release clause of £30.6m after seeing an offer of £23m rejected by the Basque club.
After failing on other targets, De Rossi's name remained in the frame right up until the closure of the transfer window, but United could have potentially got their man had they made their interest in the Italian known sooner.
Roma boss Rudi Garcia said: "We spoke when he came back from his holidays and we said that, if it got past a certain date, he would certainly remain with us.
"He will stay here for the whole season and this is something that satisfies me a lot."