By Tom Fordyce

Milan's Kaka leads the Champions League scorers with seven goals

Manchester United are out to avoid a third Champions League semi-final exit at the hands of Italian side Milan when the two sides meet at Old Trafford.

With both sides packed with talent - Kaka, Alberto Gilardino, Cristiano Ronaldo and Wayne Rooney to name but a few - the scene is set for an epic tussle over two legs.

Alberto Zaccheroni enjoyed a successful career in Serie A - leading unheralded Udinese to third place in 1998 and then moving to Milan and helping them win the title the following season.

Here Zaccheroni shares his insights on how the two giant sides will prepare for the match.

Zaccheroni says: Kaka is Milan's greatest attacking threat, not only because of his skill but also because of where he likes to play - in between the opposition's defence and midfield.

That makes him very hard to pick up, especially for a team set up as 4-4-2.

United's best chance of keeping him quiet is to stay as compact as possible through the middle, minimising the space between the two lines of the back four and the midfield.

Deny Kaka the space to operate and you make it much harder for him to weave his magic.

It sounds obvious, but these two are absolutely top players, and it's very difficult to stop them.

That's what sets apart the best players - you might be aware of what they can do, but they are good enough to get around your plans.

Milan will almost certainly look to use the energy and commitment of Gennaro Gattuso and Massimo Ambrosini, and detail them to put as much pressure as possible on Rooney or Ronaldo as soon as they receive the ball.

They'll also look to double-up against them, creating a two versus one situation so the United man has no space in which to use the ball and no time to do anything with it.

I expect Milan to adopt a 4-3-2-1 formation at Old Trafford - otherwise known as the Christmas tree.

It gives them a lot of solidity at the back and in the midfield, and also allows them to use two attacking midfielders like Kaka and Clarence Seedorf.

They are likely to play a lone striker up front and use the pace to get behind the United defence and exploit little balls played into space.

Milan will have two main concerns: United's threat on the counter-attack, and the passing of the central midfield pair of Paul Scholes and Michael Carrick.

Zaccheroni won the Serie A title with Milan in 1999

It might sound strange talking about United's counter-attack when they are at home in the first leg, but they have so much pace and skill on the break that they can be devastating - particularly through Ryan Giggs, Ronaldo and Rooney.

In terms of Carrick and Scholes, Milan will make it a priority to deny them any space.

They will aim to starve them of possession and then, when they have the ball, to close them down as quickly as possible.

They will also be wary of the runs of Carrick and Scholes from deep areas into goalscoring positions, which is something which has brought United a lot of success this season.

Simple - for United it will be the attacking threat and unpredictability of Ronaldo and Rooney, and for Milan Kaka and Andrea Pirlo.

If either side can negate the opposition's main attacking threats, they will go a long way towards booking their place in the Champions League final.