Roy Keane vented his frustrations after Manchester United were dominated in the first half of their clash with Liverpool.

Casemiro made two critical mistakes in the first 45 minutes at Old Trafford as Arne Slot's side capitalised to assume a comfortable lead thanks to a brace from Luis Diaz.

The Brazilian was summarily replaced at half-time, with the Dutchman opting to bring on 20-year-old Toby Collyer in the five-time Champions League winner's place. 

Speaking on United's performance at half-time the former United captain insisted the hosts were 'all over the place'.

'Same old problems, leopards and spots.' Keane said on Sky Sports.

Manchester United endured a dismal first-half performance against Liverpool on Sunday

'They look very open when they've been, sometimes it's just one or two passes. They got away with the first couple of this alone. 

Obviously there has been mistakes. Mistake from Casemiro, for all his experience, that's not a first time pass. It's not worth the risk. 

'And of course, when they lose it, they're all over the place. A player can make a mistake, but they've got to right back. They're all all over the place, and they've done this for the last couple of games.'

'The mistake Casemiro makes for the second one, the first goal, he gives away. I definitely think he should take a touch and with that situation, for all his experiences, awareness, he's got to do it quickly. 

'He must be aware of what's around him, and then in defence, after this United do, if the the defenders back and the players back for the second mistake. 

'But that's the world class pass from Salah to finish, but Casemiro, for that incident there, he's got to do it quickly for the first goal, I think he's got to take a touch.'

The game went from bad to worse for the hosts early in the second-half as Mo Salah added a third for Liverpool on 56 minutes.