PHOENIX -- The support David De Gea receives from Manchester United supporters is one reason teammate Ander Herrera believes the goalkeeper will stay with the club.

De Gea, who is on holiday in Miami and is due to join the tour of the United States next week, came in for some harsh criticism in Spain for a few less-than-stellar performances at the World Cup.

The 27-year-old was credited with making just one save as Spain were dumped out by hosts Russia in the knockout round.

De Gea also continues to be linked with a move to Real Madrid, but close friend Herrera has suggested the goalkeeper would rather play in England in front of United's fans.

"I remember that difficult summer when everyone was talking about Real Madrid and he played the first game at Old Trafford and everyone was singing his name and he told me 'this is amazing, they are the best'," said Herrera.

"He can be very calm but he's the best. He will show it again. He's the best keeper I've ever seen in my life and he is with us so we have more chances to win titles."

Manchester City FC/Man City/Getty Images

De Gea has a year left on his contract at Old Trafford with United holding an option to extend it by a further year, which would effectively keep him at the club until at least 2020.

Sources have told ESPN FC that United are keen to extend his deal even further. And Herrera insists there is no reason why De Gea would not agree to fresh terms, while backing him to bounce back from his World Cup woe.

"He is so so strong," said Herrera. "I remember when I was in Spain and he signed for the club. The first couple of months were hard for him and he became the best goalkeeper in the world in the next four years so I am very relaxed about him.

"We are very lucky to have him because he is the best in the world. I don't care what the critics say.

"He is the best goalkeeper in the world, by far, and he will show it again. When you are the best goalkeeper in the world and you don't make those amazing saves, everyone is going to talk.

"When I don't play very well, I don't get that criticism because I am not one of the best in the world, but he is, so it's normal and he will cope with it."

Herrera's own future has been the source of speculation this summer with former club Atletico Bilbao linked to a move for the Spanish midfielder.

He has a year left on his contract after the club triggered a 12-month extension last season, but will face extra competition for a place in United's midfield next season after the £47 million arrival of Fred from Shakhtar Donetsk.

However, Herrera, 28, is adamant he wants to stay.

"I am happy in the club," he added. "I love the fans. I am playing for the best team in the UK so my first intention is to stay in the club because I love what I do and I love where I am."