Gary Neville believes that Manchester United will need three or four signings to challenge Chelsea for the Premier League title next season.
United all but secured their place in the Champions League for next campaign with victory over Crystal Palace on Saturday as they moved seven points clear of fifth-placed Liverpool.
However, Louis van Gaal's men are 15 points behind the Blues, who have already wrapped up the top-flight crown, and Neville feels that it will take more than Memphis Depay to close the gap.
The former United captain told Sky Sports News: "What they have to do next season is challenge and get closer to the title. For Louis van Gaal, this season is par. He has done exactly what he wanted if he completes the job in the next couple of weeks and gets into the Champions League.
"It looks like he's going to do it. They've already started buying the players. Depay has come in already so it looks like they're going to be aggressive and on the front foot in the transfer market again.
"It needs that really. If you look at Manchester United's squad at this moment in time it won't get close to Chelsea, as it currently is. But with three or four signings – the right ones – then they can challenge Chelsea for the title next season. Arsenal and Manchester City will feel the same."
United will secure their place in the Champions League next season if Liverpool lose to Chelsea at Stamford Bridge later today.