Nani, 27, joined the Red Devils from Sporting Lisbon in 2007 for £20m and was tipped to be the next Cristiano Ronaldo, but has widely disappointed during his time at Old Trafford. Having failed to nail down a place in the team over the last couple of seasons, Nani has gone back to his native Portugal - despite signing a new five-year contract at United a year ago.
With new manager Louis van Gaal looking to overhaul his squad in the remaining 12 days of the transfer window, more players are tipped to leave as players come in - as was the case with Argentine World Cup star Marcos Rojo. The squad at United is large, so who could leave the club in the coming days?
The Brazilian midfielder arrived at United at the same time as Nani seven years ago, but whilst he was an exciting attacking midfielder at Porto, he's widely been known as a robust midfielder at United. Weight and fitness problems have diminished his impact at Old Trafford, and having been sent out on loan to Fiorentina in the second half of the season, it seems clear that the 26-year-old has no future at the club.
Hernandez appears to be fourth choice behind Wayne Rooney, Robin van Persie and Danny Welbeck at United, but was handed a chance to impress after the latter two missed the game against Swansea through injury. Yet after just 14 touches in the first half, Hernandez was hauled off at half time. With his national team boss urging him to leave for first team football, a number of clubs could be interested.
Belgian right back Vermijl joined the club from Standard Liege in 2010, but has made just one appearance for the Red Devils. A loan spell at NEC Nijmegen gave him the chance to impress, and whilst he did just that, Vermijl revealed how he was upset by his first encounter with new boss van Gaal.
"Van Gaal took me aside and said he would take two players per position to the US. In my case that would be Rafael and Chris Smalling at right back. It's a limited group," said Vermijl. "He said, 'I could take you but you wouldn't get any minutes'. I had imagined my first encounter with Van Gaal would be different."
Another Belgian, another potential exit. The former Everton man joined United for £27.5m almost a year ago after David Moyes scrambled for a central midfielder, but his almost comically bad first season has left the 26-year-old out of the picture under van Gaal. A loan move to Napoli has been mooted, but whilst that deal looks dead, a number of other clubs could look to get the best out of Fellaini.
The man who will go down as Sir Alex Ferguson's last ever signing at United has done little to justify his £15m fee, with reports of a bad attitude and lack of work ethic. The former Crystal Palace winger spent the second half of last season on loan at Cardiff City and once again failed to impress, and a return to Selhurst Park has been strongly rumoured in recent weeks.
Which players should van Gaal look to sell before the transfer deadline?