José Mourinho was in deferential mood again when discussing Manchester United’s quality compared with Real Madrid, saying the Europa League is very difficult to win but “top quality” lies in the Champions League.

The manager’s standout remarks of the summer tour of the United States came after last month’s 1-0 defeat by Barcelona in Washington DC.

Mourinho’s side had been outclassed during a first half when Lionel Messi, Luis Suárez and Neymar, who scored the winner, dazzled. In their previous outing United scraped a 2-1 penalty shootout victory over Real, in Santa Clara and in Washington Mourinho mentioned many of their players who are superior to his and admitted Real and Barça are a class above.

The schooling from the Catalans had shone a harsh light on precisely where United sit in the European hierarchy. Mourinho said that, as the United manager, it is up to him to outwit any superior force and so Tuesday’s Uefa Super Cup against Zinedine Zidane’s outfit is the first test of whether he and his players can meet the challenge.

United are in the match as Europa League victors and Real as European champions. Real’s supremacy was illustrated by May’s victory over Juventus that made them the first consecutive winners of the Champions League era.

After being reminded of his comments in Washington, Mourinho was asked how confident he was of being able to outfox Real in Skopje. “We are going to try, that’s obvious. But that’s also obvious the difference between the Champions League and Europa League winners. The Europa League is very difficult to win. It’s a lot of matches, you travel, the motivation is not so high. Europa League is not the El Dorado for the players.

“But the top quality is obviously the Champions League. When you get into semis-finals you have four of the best five or six teams in Europe so there is a difference in quality. It’s possible, we believe it’s possible.”

There was further acceptance of United’s inferiority when Mourinho pointed to the rare opportunity the final allows. “It’s not many times a player has a chance to play in the Super Cup unless like Barça and Madrid you have plenty of opportunities,” he said.

Juan Mata also followed his manager’s line when discussing how United rate. “We talk about Real Madrid and we talk about the Champions League winners, which is the best trophy you can win in European football,” the forward said. “They are the ones that everyone wants to beat. They have a great team and won the league in Spain as well. We know how good they are.

“But United have a great history and a great record of titles. We want, sooner rather than later, to be where Real Madrid were last season which is in the Champions League final. We know we are on our way and building a strong team. I think it’s not very big [the gap]. We are talking about the best teams in the world, Real Madrid, Barcelona, Bayern Munich. Manchester United is there.”

That tour win over Real came without Cristiano Ronaldo in the opposition’s ranks. The 32-year-old has been on an extended break but Zidane sounded an ominous note when discussing his talisman who has travelled to Macedonia.

“He’s relaxed and what impresses me the most is that he’s as fit as the day of the [Champions League] final two months ago,” said the manager. “What interests me in the long run is that he’s fit. The fact he’s with us means a lot. If he’s with us, it’s because he’s ready to play. We’ll see whether he plays or not but the important thing is he’s with us.

“I think the team is feeling well. We’re eager to start the season. This is the first official match. We’ve been working and resting very well; now is when everything starts.”

Mourinho has never won the Super Cup and would surely love to do so against the club he left in unhappy circumstances four years ago.

Mourinho clashed with several Real players but brushed off the notion he holds a grudge. “My problems in football never go beyond the world of football,” he said. “I have absolutely no problem with anyone because I no longer work for them. I have a relationship and friendship with some of them that has continued through the years, not just Real Madrid. If you ask about players at Chelsea, Inter and Porto, there are some I have maintained a relationship and others not.

“If we meet in the tunnel or near the bus, is there anyone I would refuse to say hello to? Absolutely not. I’m very happy to be able to play the European Super Cup and play against the European champions. What’s more when that European champion is the team with the best history and record and trophies, of course I get excited about that.”

His and United’s emotion will rocket if they can beat Real and claim the trophy for a second time. It will be tough but this is exactly the level of examination Mourinho and his team require.