Gary Pallister has urged Manchester United to "fight tooth and nail" to keep David de Gea at the club.
The Spaniard has been linked with a move away to Real Madrid this summer following his impressive performances for the Red Devils over the past two seasons.
However, Pallister believes that Louis van Gaal needs to keep the 24-year-old at Old Trafford along with striker Robin van Persie, while also adding four players to his squad.
He is quoted as saying by the Daily Star: "There has been a lot of talk about Robin van Persie's future so we hope that he stays. But I believe the team needs a new centre-forward, a strong midfield player, a right-back and possibly another centre-half.
"And on top of all that, you hang on to the hope the keeper stays. People keep saying if you lose De Gea you'll get Gareth Bale, but goalkeeping is such a specialised position that you have to do what you can to keep hold of one of the world's top three goalkeepers.
"I hope United fight tooth and nail to get him a new contract because he has been sensational. He earned the club a hell of a lot of points last season and probably kept them in the Champions League position. When the team was out of form he was the man who got us results."
United have been linked with a move for Real defender Sergio Ramos.