Ferguson says Barca "have more maturity about their team now because I think winning that European Cup was a big step forward for them as a team." Barcelona captured a third European title with a 2-0 victory over United in 2009, with Lionel Messi scoring the second goal.

Ferguson says "Messi running midfield ... made it very difficult for us." United and Barcelona are chasing their fourth European titles on Saturday.

Ferguson says "concentration is going to be very important in dealing with all the issues in terms of attacking and defending."