Barcelona's players believe Manchester United have improved since the departure of Cristiano Ronaldo to Real Madrid in 2009.
Ronaldo played his last game for United in the Champions League final in Rome - which Barca won 2-0 - before sealing an £80million switch to the Bernabeu.
United ended up with only the Carling Cup in their first campaign following the Portugal forward's exit, but this season has seen Sir Alex Ferguson's side reclaim the Barclays Premier League title and progress to the final of the Champions League to face Barca on Saturday at Wembley.
"Their team isn't as direct as before; they like to have the ball," Barca midfielder Xavi said.
"I don't know if that's because of Cristiano Ronaldo or not, but they move around as a unit now."
Striker David Villa added: "Cristiano Ronaldo's departure has liberated them.
"Many great players come and go and that has allowed them to remain at the top for so long."
Wing-back Davi Alves reckons United's threat is harder to nullify in the absence of the Portuguese.
"This Manchester United team is much more unpredictable without Cristiano Ronaldo," he said.
"They have formed a more balanced group and they are stronger than they were two years ago."
Andres Iniesta also believes United have improved.
"They have grown as a team," said the midfielder. "They are dominating in England and now they are fighting for the Champions League.
"Cristiano Ronaldo has left, but apart from that I don't think they have made big changes and they are always competitive."
Coach Pep Guardiola sees little difference to the side Barca beat in Rome.
"It's the same team. Only one player is missing from the team that started in Rome," he said.
"Only Cristiano Ronaldo has left from that team. (Carlos) Tevez isn't there any more either, but he didn't start in Rome."
Brazilian full-back Sylvinho, who started in the 2009 final for Barca but is no longer with the Catalan club, says the two teams are similar to the ones that met two years ago.
"The squads haven't changed much," he told Sport.
"Cristiano Ronaldo isn't there any more, but United are stronger as a team."
The Barca team will travel to London this evening - two days ahead of schedule - due to fears of volcanic ash from Iceland drifting towards England.
A Barca statement read: "To avoid possible disruption due to ash from the volcano Grimsvotn, the Barca first team will travel to London today at 2200hrs [2100 BST]."
The eruption of the Grimsvotn volcano has already led to airlines cancelling a number of flights to and from Irish and Scottish airports.
Barca were forced to travel by bus to Milan to face Inter in the semi-final of last year's competition after flights were cancelled due to the ash cloud which covered much of western Europe. Jose Mourinho's Inter won 3-1 at the San Siro and went through 3-2 on aggregate.Reuse content