Kleberson knows all about the difficulties of making a positive impression at Manchester United, and he has been trying to explain the struggles endured by Fred and Andreas Pereira.Back in 2003, after seeing the midfielder become a World Cup winner a year earlier, the Red Devils invested £6.5 million ($8m) in the Brazil international.But Sir Alex Ferguson saw little return on that investment, with Kleberson making just 30 appearances across two seasons at Old Trafford. Article continues below Editors’ Picks ‘Everyone legged it on to the pitch!’ – How Foden went from Man City superfan to future superstar Emery out of jail – for now – as brilliant Pepe papers over Arsenal’s cracks What is Manchester United’s ownership situation and how would Kevin Glazer’s sale of shares affect the club? Ox-rated! Dream night in Genk for Liverpool ace after injury nightmare Some 15 years on and United were back in the market for South American talent, with Fred acquired from Shakhtar Donetsk for £52.5m ($66m).He joined fellow Brazil star Andreas in Manchester, but the 26-year-old endured a testing debut campaign in England during 2018-19.Pereira, meanwhile, has been handed fresh terms by United but is yet to fully unlock the potential he is believed to possess.Kleberson has told the us-bookies.com of two Samba stars trying to prove their worth: “Last season for Man United, Fred and Andreas Pereira had come in off the back of a good season.“When you have players from different cultures and Brazil, they play more technical, more balls to feet in a fluid Brazilian style.“When the team is not doing well, it’s tough because they may not be suited to the playing style.“When Man United play two players in the middle, it can be difficult to not see much of the ball, and because of that Brazilian style, these players may struggle. “If the team is doing well and other players are improving, this will give Fred and Pereira the encouragement to come out and play more and we see their improvement in England.”Kleberson feels Fred and Andreas need to work on becoming better suited to English football, with obvious areas of their respective games that need to be worked on by United manager Ole Gunnar Solskjaer.He added: “It would be good to see them both get on the ball more and be more creative within a game.“They need to become more athletic, and aggressive and hungry to win the ball back.“Players and fans from South America favour the technical and attacking side of the game a lot more.”Fred made just 13 Premier League starts for United last season, while Andreas was included from the off on only six occasions. Check out Goal’s Premier League 2019-20 fantasy football podcast for game tips, debate and rivalries.