Despite a goal from Wayne Rooney strikes from Nacho Monreal and former United striker Danny Welbeck saw The Red Devils crash out of the competition.
Antonio Valencia's soft back-pass allowed Welbeck in to steal the victory against the club who deemed him surplus to requirements in the summer.
Considering they were not in Europe, are out of the title race and were knocked out of the League Cup by MK Dons - finishing in the top four is now their only hope of salvaging something from this season.
Now one of the summer signings has Tweeted on the topic. Luke Shaw was signed from Southampton in the summer. He played 45 minutes of the game on Monday, but came off at half-time with a knock.
He Tweeted this today, revealing how 'gutted' he was to no longer be in the cup.
Absolutely gutted to not still be in the FA Cup.We now need to work hard to finish the season strong. Thanks to all the fans sticking by us— Luke Shaw (@LukeShaw3) March 11, 2015
He should be. Because with Chelsea and Manchester City out of the competition United had a real chance of lifting the trophy come May. Instead, they will be lifting up nothing accept, hopefully, for three teams above them in the league table.