Wayne Rooney v Alessandro Nesta

Rooney ended a lengthy goal drought in the competition when he scored at the Olympic Stadium in United’s first-leg quarter-final defeat against AS Roma - and he netted again in the 7-1 thrashing of the Italians at Old Trafford. His strength, pace, shooting and ability to run with the ball will trouble Milan, who will be keen to test his temperament.

Once reckoned the world’s best centre half, Nesta has been in unusually mediocre form for much of a season in which Milan have also been below their best. However, he has the experience and intelligence required to keep Rooney in check.

Paul Scholes v Andrea Pirlo

Pirlo and Scholes will dictate the pace at which the two legs are played.

Scholes missed the second-leg rout of Roma through suspension but he will be welcomed back by Sir Alex Ferguson for the semi-final. His snappy passes in the congested midfield area allow United to exploit the pace and movement that have defined their approach under the Scot. Just don’t ask Scholes to tackle.

The Italy midfielder can unlock any defence with his accurate passing and is one of the world’s most dangerous free-kick experts, although he has been accused of going missing in big games in the past.

Cristiano Ronaldo v Kaka

They may spend little time in direct combat over the two legs, but whoever of this pair impresses the most is likely to join his team in the final in Athens on May 23.

Opposition sides have found Ronaldo unplayable for much of the season and his trickery, pace and fierce shooting make him a serious threat to Milan.

Kaka may be slightly less eye-catching in his work than the Portuguese - but he is equally as lethal. The competition’s top scorer with seven goals this season, he is Milan’s creative lynchpin around the penalty area and their biggest goal-scoring threat. His goal against Celtic at the San Siro in the last 16, when he ran with the ball from the halfway line before converting, showed the brilliant Brazilian at his best.