If it is remarkable to hear Sir Alex Ferguson suggesting that his squad may be the best in Manchester United's history it is nothing short of astonishing that Sir Bobby Charlton agrees with him.

And it would be fitting in this of all seasons if the current United side could live up to Charlton's praise by winning the Champions League.

It is lost on no one that this is the 50th anniversary of the Munich air disaster when, by Charlton's own account, some of the greatest English footballers ever were among the dead.

The stunning quality of Sir Matt Busby's side 10 years later, and the remarkable talents of the Treble winners of 1999 also stand out in the club's history.

However, Charlton - a survivor in 1958, a winner in 1968 and one of the most emotional men in the Nou Camp when United lifted the trophy in 1999 - believes this side can go onto even greater heights.

"When Sir Alex says that this is possibly the best group of players in our history I have to agree with him" said the 70-year-old.

"How often do you hear a coach say that he's happy with his squad?

Managers are famous for always wanting one more player but right now I think we've been absolutely blessed with the extraordinary skills of Wayne Rooney and Cristiano Ronaldo and all the others.

"Really, Ronaldo is magnificent. He's like a nerve centre of English football this season - really I've never, ever seen another player like him."

United face a huge test of their continental credentials when they face Barcelona in the first leg of their Champions League semi-final at the Nou Camp.

And although they are the form team in Europe, one look at the history books could give them cause for concern.

For all Sir Alex Ferguson's success in his 22 years at Old Trafford he has won only one of his previous four semi-finals in this competition - against Juventus in 1999.

Could they, dare they, might they mess it up again? "There's no doubt at all in my mind that both United, and indeed Barcelona, have failed to win as many European Cups as either club desired or expected across their history," said Charlton.

"Sir Alex has stated it and again I agree with him, that United should have won many more Champions Cups. I hope that one of these two clubs, particularly United, can reduce that deficit this season."

Charlton thinks that the biggest threat to United comes from Lionel Messi - a player he greatly admires. "Messi is simply marvelous and the fact is that I got to know him a couple of years ago," said the 1966 World Cup winner.

"He's a fantastic lad who lives, breathes and eats football. You can see that he just loves the challenge of getting past every defender who wants to stop him and in a match like we face against Barcelona, where anything could happen, he'll be a central part of what should be the best semi-final you could possibly watch."

The last time United played in this stadium they recorded possibly the most remarkable result in their history - 1-0 down with Lennart Johannsen tying Bayern Munich ribbons on the Champions League trophy, 2-1 up before anyone could believe it.

However the last time United played Barcelona on this pitch Ferguson admits: "It was such a fantastic game of football that there were periods when I thought we might lose by 10 goals - and some when I thought we might win by 10."

That game in 1998 ended 3-3 and although there are no guarantees of a goalfeast tonight, the fact Barcelona have proved suspect at the back in recent games and that Wayne Rooney has overcome a hip injury, give United hope of at least getting a vital away goal.

United suffered a scare yesterday when Nemanja Vidic missed a large part of the final training session due to a stomach upset but he should be okay to partner Rio Ferdinand in defence.