It is an easy mistake given that slight five-foot-six-inch frame – but could lead to a few difficult moments in training. As former Shakhtar assistant Miguel Cardoso tells The Independent, Fred has “balls of steel”.

“He’s very brave and, in challenges, so strong.”

The 25-year-old will likely add more than steel to United, though. Fred will also add that high-grade oil, to make them a much slicker, free-moving side. That is another of his strengths – and he has many of those that Jose Mourinho most specifically wants this summer.

How will Manchester United line up this season? Show all 12 1 /12 How will Manchester United line up this season? How will Manchester United line up this season? How Manchester United could line up this season? Getty How will Manchester United line up this season? GK: David de Gea United's outstanding player year in year out, De Gea was the reason for last year's impressive defensive record. Getty How will Manchester United line up this season? RB: Antonio Valencia Michael Carrick's replacement as captain and a faithful servant, but "too much holiday" has left Valencia unfit to start the new season. Getty How will Manchester United line up this season? CB: Eric Bailly United's best centre-back on his day, his progress at Old Trafford has been hampered by persistent injury problems. Getty How will Manchester United line up this season? CB: Phil Jones After the frustration of missing out on a centre-half, Mourinho will have to turn to his existing options. Jones can be error-prone but, when fit, is probably the best of them. Getty How will Manchester United line up this season? LB: Ashley Young United's failure to land a left back means Young, naturally a winger, is likely to continue in a makeshift role this term. Getty How will Manchester United line up this season? CM: Nemanja Matic Perhaps the most successful of Mourinho's second season acquisitions, Matic screens the back four well but can struggle against intense pressing. Getty How will Manchester United line up this season? CM: Fred A new arrival from Shakthar Donetsk, Fred also courted interest from Manchester City before signing on at Old Trafford. Getty How will Manchester United line up this season? CM: Paul Pogba A mixed first year back at United was followed by a difficult second. Fred's arrival could, in theory, allow him to express himself better. Getty How will Manchester United line up this season? RW: Jesse Lingard A player who has made the most of the opportunities handed to him, Lingard has now finally established himself and won the trust of all at Old Trafford. Getty How will Manchester United line up this season? LW: Alexis Sanchez January's marquee arrival from Arsenal has underwhelmed initially, but could find his best form after a much-needed summer break. Getty How will Manchester United line up this season? ST: Romelu Lukaku 27 goals in 51 appearances during his first year with United was a reasonable return and Lukaku has more than enough quality to improve on that record. Getty

The United boss has been primarily concerned with bolstering his midfield in this window, and particularly wants a player to create a more fluid link between Nemanja Matic and Paul Pogba. That necessitates fine positional sense, strong tackling and quick passing, all under Mourinho’s wider demand that any new players signed be “warriors”, who follow his tactical instructions like soldiers.

Cardoso, however, feels Fred is “perfect” for this.

“He is perfect, perfect,” the Portuguese coach enthuses, having worked at Shakhtar for Fred’s first four years there before moving on to become the much-admired coach of Rio Ave. “If Fred needs to fight, he’ll fight. When he needs to play, he plays. He’s very brave, very brave.

“He’s a player with great ambition, that doesn’t have a fear of playing in any situation, any context. He is the type of player that, when things are going badly, you can give the ball to him. He has balls of steel - to use the expression. He has such a strong nerve.

Fred is expected to star for Brazil at this summer's World Cup (Getty)

“His technical capacity is enormous. And in challenges, as I say, even though he’s small, he’s strong. But the real positive to him being small is that he doesn’t have a problem playing in tight spaces, and coming out with the ball to drive play.

“He’s also excellent box to box, has that energy, and is so good tactically. He has a deep understanding. When Paolo [Fonseca] arrived at Shakhtar, he liked him a lot.

“So, whatever Jose will ask of him, he will try to do it well. He’s also decisive, that I think Mourinho will like. He plays for the team. If he has to do something on the pitch, he’ll do it. If they ask him to make that connection between Matic and Pogba, I’m sure he’ll do it well.

“He has all the ingredients required to take his Shakhtar game to United, a player with extreme quality.”

There’s also the wider issue of how he takes to the Premier League and the pressures of a club like United, but Cardoso doesn’t foresee that being any kind of complication.

Premier League summer transfer targets Show all 16 1 /16 Premier League summer transfer targets Premier League summer transfer targets Gareth Bale (Real Madrid to Manchester United) TOPSHOT - Real Madrid's Welsh forward Gareth Bale celebrates after scoring the the 3-1 during the UEFA Champions League final football match between Liverpool and Real Madrid at the Olympic Stadium in Kiev, Ukraine on May 26, 2018. (Photo by Sergei SUPINSKY / AFP) (Photo credit should read SERGEI SUPINSKY/AFP/Getty Images) AFP/Getty Images Premier League summer transfer targets Jorginho (Napoli to Manchester City) Getty Premier League summer transfer targets Toby Alderweireld (Tottenham to Manchester United) LONDON, ENGLAND - FEBRUARY 07: Toby Alderweireld of Tottenham Hotspur waits in the tunnel prior to The Emirates FA Cup Fourth Round Replay match between Tottenham Hotspur and Newport County at Wembley Stadium on February 7, 2018 in London, England. (Photo by Tottenham Hotspur FC/Tottenham Hotspur FC via Getty Images) Tottenham Hotspur FC via Getty Images Premier League summer transfer targets Kylian Mbappe (PSG/Monaco to Manchester City) Kylian Mbappé has already hit 19 goals this season Getty Premier League summer transfer targets Alex Sandro (Juventus to Manchester United) Real Madrid's Spanish midfielder Lucas Vazquez (L) vies with Juventus' Brazilian defender Alex Sandro during the UEFA Champions League quarter-final second leg football match between Real Madrid CF and Juventus FC at the Santiago Bernabeu stadium in Madrid on April 11, 2018. / AFP PHOTO / PIERRE-PHILIPPE MARCOU (Photo credit should read PIERRE-PHILIPPE MARCOU/AFP/Getty Images) AFP/Getty Images Premier League summer transfer targets Leon Bailey (Bayer Leverkusen to Manchester City) Getty Premier League summer transfer targets Riyad Mahrez (Leicester City to Manchester City) Getty Premier League summer transfer targets Nabil Fekir (Lyon to Liverpool) Premier League summer transfer targets Robert Lewandowski (Bayern Munich to Chelsea) Robert Lewandowski's time at Bayern Munich looks to be coming to a close Getty Premier League summer transfer targets Alisson (Roma to Liverpool/Chelsea/Arsenal) Alisson will be going nowhere this summer Getty Premier League summer transfer targets Steven N’Zonzi (Sevilla to Arsenal) MADRID, SPAIN - APRIL 21: Steven N'Zonzi of Sevilla FC looks on during the Spanish Copa del Rey match between Barcelona and Sevilla at Wanda Metropolitano on April 21, 2018 in Madrid, . (Photo by Aitor Alcalde Colomer/Getty Images) Getty Images Premier League summer transfer targets William Carvalho (Sporting Lisbon to Everton) Carvalho has been linked with a number of Premier League clubs Getty Premier League summer transfer targets Matthijs de Ligt (Ajax to Manchester City) Ajax defender Matthijs de Ligt (L) vies with Lyon's French midfielder Clement Grenier during a friendly football match between Olympique Lyonnais and Ajax Amsterdam on July 18, 2017 at the Pierre Rajon stadium in Bourgoin-Jallieu. / AFP PHOTO / JEAN-PHILIPPE KSIAZEK (Photo credit should read JEAN-PHILIPPE KSIAZEK/AFP/Getty Images) AFP/Getty Images Premier League summer transfer targets Jack Butland (Stoke City to Liverpool) England's goalkeeper Jack Butland is pictured during the International friendly football match between England and Italy at Wembley stadium in London on March 27, 2018. / AFP PHOTO / Ian KINGTON (Photo credit should read IAN KINGTON/AFP/Getty Images) AFP/Getty Images Premier League summer transfer targets Wilfried Zaha (Crystal Palace to Tottenham) Getty Premier League summer transfer targets Jan Oblak (Atletico Madrid to Chelsea) Getty

“In Ukraine, they play in bad conditions, with the snow, with very bad pitches, but his technical quality meant he was even more effective.

“Fred has a lot of Champions League and Europa League experience. In the last few years, the Ukrainian league hasn’t been as strong but Fred played in it when there was a lot of fight, and could be physical. He succeeded.”

Given that Mourinho has expressed frustrations with some of the trappings of the modern professional – with a few veiled criticisms of Pogba in that regard – this is another area where Fred could be “perfect” for his new boss.

“He knows very well what it means to be a professional,” Cardoso explains. “First of all, they’re going to get a lad who is a great man, lovely to be around. He has a way about him that everyone will love. He’s not only humble, he’s always very happy, very relaxed. Everyone will like him.

He’s a boy who’s not going to create a single problem. “Fred is a family guy. He has his girlfriend. You don’t see him out much, he’s a lovely guy. Very relaxed life.

“He is always trying to get better. At the end of training, he would always be one of the ones staying behind to work on technical aspects of his game, free-kicks - like that goal against Roma in the Champions League. He’s always looking to be better.”