Liverpool coasted to a 2-0 victory in the first leg at Anfield last week, as a Daniel Sturridge penalty and a goal from Roberto Firmino gave Jurgen Klopp's men a major advantage.
The Reds haven't played since then and come into tonight's match fresh, whilst opponents United came through a tough match against West Ham United on Sunday, a match which they drew 1-1 in the FA Cup.
Manager Louis van Gaal desperately need a win to try and get fans back on his side, and such a pitiful defeat against a fierce rival has left the Dutchman with a lot of work to do this evening.
Now, pundit Charlie Nicholas has offered his view on the game, telling Sky Sports that he thinks Manchester United will win the game 2-1, which would of course hand Liverpool a 3-2 aggregate win and send the Red Devils crashing out of the competition.
Nicholas believes that Juan Mata is the key to United's chances of claiming a win, whilst also highlighted how dangerous forward Anthony Martial is, having scored in the draw with West Ham on Sunday.
The pundit also expects a busy night for the referee after a spiky encounter at Anfield last time out, and thinks tensions could boil over this time, leading to red cards at Old Trafford.
"This tie isn't over, but Manchester United need to start quickly and score first if they are to have any chance of progressing," said Nicholas. "Liverpool will be happy to drop off, pack the midfield and squeeze when they're in their own half and Juan Mata is the key to unlock the defence."
"Marouane Fellaini was lucky to not be sent off in the first leg and I wouldn't be surprised if things boil over and we get a red card here, especially if Liverpool get the away goal and United get frustrated."
"Anthony Martial is looking more dangerous and he is definitely United's main dangerman now. He's key for them to have any chance of pushing this towards extra-time, which I wouldn't be surprised to see. I expect them to win the game, but go out," he added.
What's your prediction for Manchester United v Liverpool?