David de Gea
David de Gea risks disappointing fans of former club Atletico Madrid if he moves to Real Madrid this summer, reveals Tomas Ujfalusi Getty

Former Atletico Madrid defender Tomas Ujfalusi has warned David de Gea that he risks alienating fans of his former club if he moves to inter-city rivals Real Madrid this summer.

The Spanish goalkeeper started his career with Atletico, before moving to Manchester United in 2011 for a reported £18.9m ($29.4m). After a tough start to his career at Old Trafford, he is now considered one of the top goalkeepers in the world, which has attracted interest from the 10-times European champions.

Real Madrid are keen on signing the goalkeeper this summer, with the club increasingly confident of landing De Gea, who according to the Daily Mail, has already told friends that he wants a return to Spain ahead of next season.

However, United are holding out for a record transfer fee from the La Liga club for their number one stopper, who has just a year remaining on his current deal.

Ujfalusi was De Gea's teammate at Atletico during their 2011 Europa League winning campaign and has warned him against joining their bitter rivals.

"No, no, no. They are not going to forgive him [if De Gea joins Real Madrid], for sure," Ujfalusi said, as quoted by the Daily Mail.

"It's not going to be easy for him to make this decision. It's also a surprise for me because he's an Atletico Madrid fan – when he was young his heart was with Atletico Madrid," the now retired defender added.

The former Galatasaray defender feels that the Spanish international stopper is the best in the Premier League at the moment, but admitted that it was difficult to compare him to Petr Cech, who has proved himself during his just concluded 11-year stay at Chelsea.

"I have to say De Gea [is superior to Cech and Courtois]," the former Czech Republic international said.

"I was working with him for more than two years, and he was playing really well."

"It's difficult to say, but Petr Cech is 10 years older than De Gea and Courtois."

"The beginning in Manchester United wasn't so easy for him, but I think now he's back in his old form and playing very well," the 37-year-old defender explained.