Matches between Manchester United and Arsenal have often made icons out of players and tonight Theo Walcott has the chance to join the pantheon of greats provided by the two best footballing sides in the country.

Eric Cantona, Marc Overmars, Sylvain Wiltord, Ryan Giggs, Roy Keane, Patrick Vieira, Ruud van Nistelrooy and Martin Keown all stand among them - and that's just from the Premier League era.

Walcott was on the verge of a breakthrough season perhaps chiefly thanks to his stunning hat-trick for England in Croatia last October before a four-month absence with a shoulder injury curtailed his momentum.

The 20-year-old from Stanmore remains a wealth of unfulfilled potential yet the likely expansive nature of tonight's encounter should provide him with the space to blow this Champions League semi-final wide open.

Extra encouragement can readily be found in Patrice Evra's total inability to marshal the pace of Tottenham winger Aaron Lennon twice in the last two months, given Walcott has still more speed at his disposal.

Arsene Wenger must be taken at his word that Arsenal will attack and the visitors have a devastatingly direct weapon which United, for all their many attributes, can not quite match.

The Arsenal manager said: "He gives us something important in the balance of the side. Obviously Theo can score but that is not predictable. I don't really mind who scores the goals - the important thing is that we score at all.

"The rules in Europe are made to make teams audacious away from home and score goals. That's why I believe to score an away goal will be important.

"I believe United can concede goals and that is always good. I only saw the first half of their game with Tottenham on Saturday. They had a little problem at the start and conceded two goals - I didn't see the second half."

It seems more than a little ironic that Wenger 'didn't see it' given United roared back to smash five past a bewildered Spurs but perhaps in his mind it was enough to identify a defensive vulnerability in an opponent that start the game as marginal favourites.

Ferguson and Wenger agree on much these days but the Scot dismissed the idea Evra would struggle to handle the threat posed by Walcott and rejected any idea that Spurs had provided their north London rivals with the blueprint to score at Old Trafford.

He said: "Patrice is quick enough and has played against Walcott a few times. We're okay with that. When you are playing against good players, you are going to assess everything about them.

"We have to do our work in that respect because the boy Walcott is very quick, probably the quickest forward in England, but we just have to prepare the right way.

"There's always a way of analysing goals you lose to suit yourself but, in all honesty, I thought it was a bit fortuitous that Tottenham scored their first goal and it gave them a great filip to score another."

United v Arsenal matches used to be season-defining tussles but the rise of Chelsea - and Liverpool's resurgence this season - has diluted the duopoly the pair have enjoyed at the top of the English game.

Ferguson and Wenger's recent entente cordial is born out of Arsenal's inability to deliver a serious title challenge but even during the Gunners' recent underachievements, they remain evenly matched.

For Arsenal's 20-game unbeaten League run, read United's 23 matches without defeat in Europe dating back to May 2007. Wenger and Ferguson have met 37 times, with the former edging the victory count by 14 to 13.

There is little these two rivals can do to surprise one another tactically and that goes some way to explaining why so many of their matches have been decided by a moment or two or unpredictable and undefendable quality.

Arsenal are likely to sit deep and attack on the break and who better to have than Walcott to carry out such a game plan? In last season's Champions League quarter-final exit at Liverpool, the winger nearly had his moment.

A dazzling run carved Rafa Benitez's men apart and a simple but effective square ball gave Emmanuel Adebayor a tap-in and Arsenal a place in the last four, only for two late strikes to deny the winger his coming of age.

Walcott needs to improve his touch and his decision-making but now is the time for him to come to the fore.

Should he need a reminder of the level required, he can glance over to the opposition where he will see Ryan Giggs, who is expected to make his 800th United appearance tonight with his place among the greats of this fixture already assured.