Early goals from Naby Keita and Diogo Jota put the visitors in control of the contest early on, before Mohamed Salah became the first player in Premier League history to score an away hat-trick against Man United at Old Trafford.
Ole Gunnar Solskjaer's future has once again come under scrutiny following the result, and Souness has questioned whether the team have a way of playing under the Norwegian.
"I hate calling out managers, because it's not an easy job to do at a big football club, but that looks like a group of players... they need to have a week of never seeing the ball and just doing positional play," Souness told Sky Sports News.
"'What do we do when the ball's here? What do we do when the ball's there?' Yeah, they're all technically gifted but they don't look like they have a way of playing."
Solskjaer has already ruled out the possibility of resigning from his position following the defeat.