Manchester United must break the bank for John Stones and Raphael Varane says Rio Ferdinand

Manchester United must complete deals for Everton centre back John Stones and Real Madrid defender Raphael Varane, according to former England captain Rio Ferdinand. The Old Trafford club have been heavily linked with both players in the past and have been urged to sign the pair in order to kick-start their resurgence.

The Manchester Evening News understands that Louis van Gaal will attempt to lure France international Varane away from Real during the upcoming summer transfer window after the club previously missed out on signing a player who already has an impressive reputation. The 22-year-old was signed by Jose Mourinho from Lens in 2011 and the Portuguese boss says he is the best defender in world football.

Stones meanwhile has been linked with a £50m ($72m) move to United, according to The Independent, after Chelsea missed out on signing the England international during the last summer transfer window. The Premier League champions made four bids for the ex-Barnsley centre back during off-season but were met with a stern resistance from Everton.

"I don't care how much it is," ex-United defender Ferdinand said, according to M.E.N. "You are getting a player for 10 years. John Stones and Raphael Varane are the best in the world. The team starts at the back. Your platform for winning titles starts in defence. If Stones goes to another English club they will regret it."

United boss Van Gaal has played down the club making any signings in the current January window, despite the disillusionment among supporters amid the team's current form. The 20-time English league champions needed an injury-time penalty from Wayne Rooney to secure victory over Sheffield United in the FA Cup third round – a game which many home fans left early in a reaction to the style of play adopted by the side.

"I cannot discuss that with you," the Dutchman responded when asked about his transfer plans following the game, according to Sky Sports. "I don't think we shall do business in January. "But you cannot say that because when there is a chance to make the selection better, we shall do it, but I don't think we shall do that. But that is this moment."