Phil Neville has suggested that David de Gea could be Manchester United's most important signing this summer, if they can agree a new contract with the Spaniard.
The ex-Atletico Madrid keeper has earned rave reviews for his performances for the Red Devils this season, but has also been regularly linked with a move to Real Madrid.
However, Neville claims that United would be retaining an integral part of their squad by keeping De Gea at Old Trafford.
He is quoted by the Manchester Evening News as saying: "The biggest thing is David de Gea, and keeping him at the football club.
"From when he first came, to how he is now, I don't think I've seen a player develop and improve as quickly as him.
"I saw with Cristiano [Ronaldo], I saw the development in terms of his performance, his size, his stature and his physique. He's now at the stage where you'd say he's world-class."
United are currently third in the Premier League.
