Former Manchester United midfielder Bryan Robson believes that Manchester United need to splash the cash in four areas of the field if they have to challenge for the title next season.

The Red Devils have done incredibly well under Louis van Gaal, securing fourth place and making their way into the qualifiers of the Champions League, where a win will take them into the group stages. Chelsea were the runaway winners last season, making minimal mistakes across the year and were on top of the league table for the maximum number of days over a season.

Robson insists that Petr Cech is the man to replace David de Gea, should he leave for Real Madrid amid massive interest from the likes of Arsenal. The keeper apparently wants to stay in London with his family settled in the capital, but a lucrative offer from United could change his mind after he dropped out of the Chelsea squad following the emergence of Thibaut Cortouis.

"It's important to bring in players as soon as possible. If De Gea has to be replaced,Cech would be ideal – he could do for the club what Edwin van der Sar did," Robson said.

"Ideally, United will be able to strengthen the back, midfield and attack. And also, hopefully, one or two of the kids will make their mark, as the likes of Ryan Giggs and Paul Scholes did," he added.

The legend also added that he is in awe of the way Van Gaal has led the team and insists that he is the man to take Sir Alex Ferguson's legacy forward in the days to come.

"Having watched Louis van Gaal at work this season I am absolutely convinced he is the right man to take United forward," he continued.

"He is very focused on what he wants and how he wants to go about it. He has given the players a very clear direction that he expects them to follow.

"I can see the similarities with Alex Ferguson – the same strong leadership and way of going about things. You always knew where you stood with the boss [Ferguson]. If anybody stepped out of line he would be down on him, get him out of the team and even move him on."