Cape Town - Manchester
United midfielder Ander Herrera believes his side are not far off Real
Madrid, who continue to be linked with goalkeeper David De Gea.
Last season’s Europa League champions have made a bright start in the Premier League, and the Spain international believes they are reaching the level of Los Blancos.
"David is really happy at the moment because we are fighting for everything," Herrera said.
"Real Madrid are going to talk about him every summer because he is the best keeper in the world. But we don't think we are far from Real Madrid.
"I respect all the keepers like Manuel Neuer, Gianluigi Buffon and Marc-Andre ter Stegen.But David right now is the number one in the world."
United will get to test themselves against some of Europe’s top teams, perhaps even Madrid, in this season’s Champions League, but first they must prepare for a League Cup clash with Burton Albion on Wednesday.
Meanwhile Jose Mourinho claimed drawing level with Manchester City at the top of the Premier League table did not enter his mind following their 4-0 win over Everton.
United have the same points and goal difference as Pep Guardiola's side after goals from Antonio Valencia, Henrikh Mkhitaryan, Romelu Lukaku and Anthony Martial secured an emphatic victory over the Toffees.
"I didn't think one single second about Man City," Mourinho said. "I thought about Tottenham, Arsenal, Chelsea, Liverpool.
"They didn't win their matches and it was a chance for us to get two points like they got last week when we drew against Stoke. I was just thinking about them, not City. City won their game, they did their job.