The Red Devils shot stopper continues to be linked with a £25m move to the 10-time European champions after having impressed for Louis van Gaal’s side last season.
De Gea moved to Old Trafford from Atletico in a £17m deal in 2011 after Sir Alex Ferguson earmarked the Los Rojiblancos youngster as the ideal replacement for Edwin van der Sar.
But De Gea’s former Atletico team-mate Ujfalusi warned the goalkeeper that there will be no going back with the Los Rojiblancos supporters if he joins the club’s bitter derby rivals.
“No, no, no. They are not going to forgive him, for sure,” Ujfalusi told the Daily Mail.
“It’s also a surprise for me because he’s an Atletico Madrid fan – when he was young his heart was with Atletico Madrid. It’s not going to be easy for him to make this decision.”
The Spain goalkeeper made 37 Premier League appearances during Louis van Gaal’s first season in charge at Old Trafford.
The Spanish shot stopper was named the players’ player and fans’ player of the year following his impressive 2014/15 campaign.
De Gea, who was signed to replace Edwin van der Sar, won the Premier League title with the Red Devils in 2013.
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