Manchester United target Sergio Ramos is a 'walking red card' says Ray Wilkins

Ray Wilkins has provided something of a warning to former club Manchester United over Sergio Ramos, claiming the Real Madrid defender is a "red card walking" as rumours of a potential transfer to Old Trafford continue to gather pace.

The World Cup winner has made over 300 appearances and won three La Liga titles since joining Los Blancos from Sevilla in September 2005, yet reports from The Guardian suggest United have named him as their price for allowing highly rated goalkeeper David de Gea to return to Spain despite the presence of an eye-watering £128m (€130m) release clause.

Real are known to be long-term admirers of De Gea, who is out of contract next summer, and see the 24-year-old as an ideal long-term replacement for Iker Casillas.

Spanish daily Marca seemed adamant that such a transfer will eventually come to pass, although it speculates that a formal transfer request could be necessary to speed the process along.

While Karim Benzema, Gareth Bale and Raphael Varane are also mentioned as being of interest to United manager Louis van Gaal, it seems Ramos has emerged as a key target with the Old Trafford club evidently having lacked a sufficiently experienced, quality central defender since the respective departures of Rio Ferdinand and Nemanja Vidic.

"Sergio Ramos has been around the block and he knows the score, especially in Champions League," Wilkins, who represented United for five years between 1979 and 1984, told Talksport.

Addressing Ramos's notably poor disciplinary record, he added: "He's a red card walking, though. He gets het-up when things don't quite go his way. Madrid have played him at full-back and as a holding midfield player, he's very versatile.

"It would be an interesting signing because the first year is always difficult when you come to the Premier League."

United have unveiled one signing already this summer, with Dutch international Memphis Depay set to reunite with Van Gaal after joining from Eredivisie champions PSV Eindhoven on a four-year contract.