Real Madrid defender Sergio Ramos is remaining tight-lipped amid links to Manchester United.

Sergio Ramos is calm over his future, as speculation mounts that the experienced Spain international defender could swap Real Madrid for Manchester United.

Ramos has emerged as a transfer target for Premier League giants United, who are preparing to play hard ball over in-demand goalkeeper David de Gea.

Real are desperate to sign Madrid native De Gea but Louis van Gaal and Co. want one of the club's prized assets in return, preferably Ramos.

Ramos, who is believed to be frustrated over an impasse on contract negotiations with the 29-year-old entering the final two years of his current deal, responded to questions over his future in Madrid on Monday, telling reporters: "I never worry."

The former Sevilla centre-back has been an ever-present for Real since arriving from Seville in 2005, amassing over 400 appearances in all competitions.

During his 10 years in the Spanish capital, Ramos has helped the club to three La Liga titles, as well as UEFA Champions League glory in 2013-14.