Getty Images While happy in Ukraine, the Brazilian wants to challenge himself elsewhere, having been linked with Manchester United and Manchester City Fred wants to make a forward step in his career after telling Shakhtar Donetsk he plans to leave amid interest from Manchester United and Premier League champions Manchester City. Brazil international midfielder Fred has been tipped to join either United or City in the close-season, having impressed domestically and in Europe this term. Goal understands City agreed a deal in principle to sign him from Shakhtar this summer, while the Ukrainian side's chief executive Sergei Palkin has said the Manchester rivals will battle for the 25-year-old , who is in Brazil's 23-man squad for the World Cup in Russia. While he is happy in Donetsk, former Internacional star Fred feels ready for a challenge elsewhere in Europe. "I'm very happy at Shakhtar," Fred told SporTV . "I've been wor