Jamie Carragher has suggested that it will take another massive outlay on new signings if Manchester United are to seriously challenge for the Premier League title.

The Red Devils find themselves down in 13th place in the early-season standings after suffering back-to-back defeats, following up their 3-2 setback at Brighton & Hove Albion with a 3-0 loss at home to Tottenham Hotspur on Monday night.

Despite spending more than £400m on players since Jose Mourinho took charge a little over two years ago, Liverpool legend Carragher expects United to fall short again this season with those available to him.

"We saw the side of United tonight where they're still fighting. The worrying thing is if you've got that in a game, and you're still losing 3-0," he told Sky Sports News.

"There's a serious lack of quality, if you've spent £400m on a squad. How do you lose 3-0? That's a team that looks like it still needs £200m spent on it. Some of the defenders there. What's happened at United in terms of buying two £30m centre-backs?

"I can't really criticise [Victor] Lindelof because it gets to the stage that he's so far out of his depth that you start to feel sorry for him.

"In terms of [Phil] Jones and [Chris] Smalling, have they improved since Mourinho came in? They've been playing for a long time, and it shouldn't really be happening at this level."

United have lost two consecutive league games and two of their opening three fixtures for the first time since 1992-93.