Sky Sports pundit Gary Neville says Manchester United have to "react fast" to their humbling defeat to Liverpool and believes Ole Gunnar Solskjaer's squad is "five or six" players short of competing at the top of the Premier League.

Sunday's 2-0 win for Liverpool saw Jurgen Klopp's side take another significant step forward towards their first league title in 30 years and United fall a staggering 30 points behind their arch-rivals.

For Neville, it is crunch time for the Old Trafford hierarchy to take urgent action to arrest United's slide.

"They have really got to react fast and that means that they have to make good decisions," Neville told The Gary Neville Podcast.

"There has been a real frustration in the last few years at Man Utd, the board have been U-turning all over the place when it comes to strategy.

"They've made some terrible investments in terms of recruitment and it's all coming home to roost and nothing brings it home more than seeing Liverpool right back at the top of that league, that is the most painful thing.

"I hope that everyone in that Man Utd executive boardroom team that they've got here today is feeling the pain of those fans and everyone else watching who is associated with the club because this is going to get bad.

1:57 The Good Morning Transfer team discuss the possibility of Edinson Cavani moving to Old Trafford. The Good Morning Transfer team discuss the possibility of Edinson Cavani moving to Old Trafford.

"This next six months is going to be really, really difficult. I can't believe that the investment that has been put into the squad over the last five, six or seven years, and you end up with that out on the pitch. I cannot believe it."

United have been hit hard in recent weeks by injury, with their problems exacerbated by confirmation that Marcus Rashford is set to be sidelined for up to three months by a double stress fracture in his back.

I can't believe that the investment that has been put into the squad over the last five, six or seven years, and you end up with that out on the pitch. I cannot believe it. Gary Neville on the Gary Neville Podcast

"It's a huge blow," said Neville. "He's been outstanding, he's a fantastic player and he's had a great season and Man Utd are going to be entering into really important games in the FA Cup and Carabao Cup, where they're up against it with Man City.

"But there's also the Europa League, where they still have the chance. Chelsea are stalling a little bit and Man Utd could get into the top four so to lose Rashford is a big problem for Solskjaer.

Solskjaer looks on during the humbling defeat at Anfield

"I don't know how they cope without him other than to try and sign somebody who can fill that gap, but it's not going to be easy because no one is going to let Man Utd pick someone off the top shelf, everyone is looking to look after their own club. They somehow have to be smart enough to get somebody in that can do a job for the club."

But according to Neville, United need far more than just extra options in attack.

"They're going to be light up front and when you look at the midfield, it's bleak. Paul Pogba has just had an operation and Scott McTominay is out too, but there's more than the midfield and a centre forward that needs changing at the club. They need a centre-back, a left-back, a wide player, there are five or six players they need in that squad.

2:12 Sky Sports News' James Cooper provides the latest on Manchester United's search for a new striker Sky Sports News' James Cooper provides the latest on Manchester United's search for a new striker

"They may need one or two in the immediate future to patch things up, a midfielder and a striker are essential because of the injuries to Rashford and Pogba, but there are other things Man Utd have to be targeting. It's a squad that has had hundreds of millions spent on it, but looks like it needs hundreds of millions more and that's the worry."

Liverpool 2-0 Man United - Free match highlights