Tim Sherwood says signing Erling Haaland or Harry Kane would make Manchester United title challengers but says their biggest transfer mistake was letting a striker of that ilk leave in the first place.
United have made a striker their transfer priority this summer with Haaland top of their wish list and Kane an alternative option.
Speaking to Premier League productions, Sherwood said that, even if veteran forward Edinson Cavani stays, United still need another striker due to the fact he will not be able to play every game.
The former Spurs and Aston Villa boss believes bringing in a player like Haaland or Kane will give them a quality striker whilst also allowing Cavani's influence and experience to rub off on younger players.
Yet Sherwood also argued that United already had a forward of that calibre in the form of Romelu Lukaku and said selling the Belgium star to Inter Milan was their biggest transfer mistake.
He said: "What they do need is a centre-forward, they're going to need someone.
"They had someone and it was the biggest mistake they've ever made getting rid of Romelu Lukaku, who's on fire now at Inter Milan.
"Edinson Cavani might not be the answer to challenge Man City because of his game-time but I think he's brilliant for the younger boys.
"For Rashford, Greenwood and Martial to watch him every day in training is great because what he does is an art.
"Who do Manchester United go for this summer? Is it Haaland or is it Kane?
"If they get one of those two in they would certainly be up there challenging for the Premier League title next year."
