The Scotsman thinks that his side have the personnel to neutralise the Argentine's threat...
"Yes, Messi is a fantastic footballer," Ferguson said. "We played against him twice last season, so we know exactly how powerful he can be. We can cope with that. We have the players to do that. It won't be easy, you have to respect great players and tomorrow we'll definitely respect him."
As for whether Messi or United's Cristiano Ronaldo was the better player, the Scotsman refused to be drawn, exchanging some humorous gestures with the Portuguese star, sitting to his right, before answering, "They're two fantastic footballers. Both with the ability and the courage to attack defenders all the time, no matter how many times they're tackled, how many times they have fouls [committed] against them, they get up and they want the ball and that's the kind of courage we love to see in footballers, and both have that.
"Both have different types of qualities. Physically they're different types of footballers, but at the end of the day how can you separate them? It's very difficult."
Ferguson will be overseeing his 153rd Champions League tie tomorrow night, but he played down the importance of his vast management experience when compared to that of his opposite number at Barcelona, Pep Guardiola.
"I think you're better to have it than not have it," the United chief opined.
"But the plus side is that Pep is at a football club that has got a great history in European football. He himself as a player had a good record in European football. I hope it matters, but it's not the most important thing tomorrow."
As for whether United's strength on the bench could make a difference in the game, Ferguson pointed out that Barcelona's squad hadn't yet been decided, with Thierry Henry and Andres Iniesta possibly missing at this stage.
"I think when we line up we have very good subs, that hopefully can make a difference if needed.
"We have to play well to in tomorrow. Certain things will be important: the concentration, a bit of luck that all teams get in certain moments of a game. Hopefully we have that little bit of luck."
And the Scotsman, who once termed Real Madrid 'Franco FC', warned any Catalans in the crowd, who might think that United's chosen all-white kit meant that another 6-2 result was on the cards, "We're better than Real Madrid."
Zack Wilson, Goal.com