JOIN US"I could not enjoy the final in Paris because of an injury I had, but, fortunately, I have a second chance now. This is the most important game in my career," he said.
Barcelona won the 2005-06 Champions League in the French capital, when they beat Arsenal.
Messi, 21, noted that Wednesday's game will be special against Man United, the same club that knocked Barca out in last year's semis.
"There are no favourites or revenge for last year," he said.
"There are two great teams full of great players. If you have to name a favourite, it would perhaps be them, because they won the tournament last year, but I expect a very open final."
He said that Barca and Manchester have been "the two teams that have played the best football all year," and stressed that their focus on attack was the key to success for both.
Barcelona has already won La Liga and the King's Cup this season, while the Red Devils have won the League Cup, the FIFA Club World Cup and the Premier League.
"They play football very similar to us. They quite like to play with the ball on the ground, and they are also very good in counterattack with extremely fast people like Cristiano (Ronaldo) or (Carlos) Tevez," Messi said.
The striker went as far as to say that his team deserves the cup, precisely because of their good football.
"I am aware of the fact that many people who are not Barca fans admire us for our football. We deserve this reward," he said.
The Argentine had to answer many questions about his own clash with Cristiano Ronaldo, since both are considered to be the world's best players.
"He is a player who can easily throw you off balance and who can settle a game anytime. He is difficult to stop, he scores many goals, he is very complete," Messi said of his Portuguese rival.
He further praised fellow-Argentine striker Tevez and French left back Patrice Evra, who is likely to mark him in Rome.
"I respect him because he is an extremely good player, as he already showed last year. Let's see what happens this time," Messi said.
Barcelona is seeking a historic treble.
"We know we are close to making history. Even if we don't manage to win, it will be a great season," Messi said. "We have our chances, both because of the players we have and because of how we have been playing all year round. We are playing spectacularly."
Messi gave his version of the key to crack the game.
"The most definitive thing is that we are able to play our game, that is, that we have possession of the ball and that we create chances. It does not matter who scores the goals," he said.
"I expect this to be an open final for the good of football and for people to be able to enjoy it."
The 21-year-old has been linked with a move to arch-rivals Real Madrid, but he has no intention of leaving Camp Nou.
"I have said so many times that I am so happy at Barcelona, and I have no desire to ever leave," he said.
"I owe them so much. I want to repay them for the rest of my career. I am loyal to Barcelona.
"The doctors at home in Argentina told my parents I would never grow past 4ft 5in.
"The medical bills were very high. My father took on other jobs but even then it was not enough for the other bills.
"Nobody else was prepared to take a chance on me apart from Barcelona and if it was not for them I would not even be a professional football player."