Man Utd's Ruben Amorim must realise Premier League is different planet to Portuguese football, says Paul Merson

Ruben Amorim must realise the Premier League is on a different planet to Portuguese football, says Paul Merson, as Manchester United prepare to face Liverpool on Super Sunday.

The manager - who replaced Erik ten Hag in November, joining from Sporting Lisbon - has struggled for results and performances since arriving at Old Trafford.

Since beating Manchester City 2-1, Man Utd have lost their last four games in all competitions, including a 2-0 defeat to Newcastle. It led Amorim to admit that his team are in a relegation fight.

Their task does not get easier either, taking on an in-form and Premier League table-topping Liverpool at Anfield, live on VidSport Live this weekend.

Speaking on The Football Show, Merson gave his view on Man Utd's current situation and why Amorim needs to adapt quickly to the rigours of the Premier League.

The way their form is, he probably does mean that they're in a relegation battle - and they've got Southampton at home in the next league game. You would expect them to win that game but at the moment, it's not a good watch.

When the teams came out the other day [against Newcastle], I thought they did well to keep it to 2-0.

[Christian] Eriksen and Casemiro have been top-drawer players, but to play them in midfield, the manager's got to get used to understanding this is not Portuguese football. This is the Premier League now. It's on a different planet to Portuguese football.

When he's set up with them in midfield against [Sandro] Tonali, Bruno [Guimaraes] and Joelinton, I thought 'these two are going to get absolutely destroyed'. And as I said, I thought they did well to only lose by two.

I don't know how much money they've got with Financial Fair Play. They've got a lot of players they need to get rid of at the same time. This is a hard job [at Man Utd].

You're talking about one of the biggest clubs in the world... but at the moment, they're all over the place.

The way he wants to play doesn't suit Man Utd. They haven't got the personnel to play the way he wants to play. The most important thing when you play three at the back is you have got to have outstanding wing-backs - and they haven't got outstanding wing-backs. Both the full-backs are good defensively, but they're not great going forward.

I've said it a few times, I think the manager would have suited Chelsea. Don't get me wrong, Enzo Maresca has been outstanding, but if you had to pick a club for him in the Premier League to play the way Amorim wants to play, you'd put him in at Chelsea. Chelsea have got a lot of centre-halves that are pacey.

They've got wing-backs that are amazing in [Ben] Chilwell, [Malo] Gusto, [Reece] James - natural wing-backs that can get forward and defend.

They've got holding midfield players with legs in [Moises] Caicedo and [Romeo] Lavia, and then they've got the talent going forward. I think he would tick the box at Chelsea. With Man Utd, I don't see how it fits.

There's so much work to be done to get to the way he wants to play and that's going to take a long time with a lot of players coming in and out. And with the way the rules are now, I don't know how that long that's going to take.

If Man Utd went and won at Liverpool this weekend, it would be the biggest shock in the Premier League.

Whatever happened in any of the other results this weekend, even if West Ham went and won at Man City, it wouldn't be a bigger shock than Man Utd beating Liverpool. That's how far it's gone.

The only thing you can hope for if you're a Man Utd fan is a 0-0. I know they went and beat Man City, but let's be honest, Man City were very comfortable up to the last 10 minutes of that match.

I worry for Man Utd. If Liverpool scored early, I dread to think what score this will be.

Watch Liverpool vs Man Utd live on VidSport Live Premier League from 4pm on Super Sunday; kick-off 4.30pm.