We pose five questions Sir Alex Ferguson will have to get right if Manchester United are to progress.
How will Manchester United approach the game?
Although Sir Alex Ferguson and Jose Mourinho both agreed that the tie is finely poised ahead of the second leg, it would be remiss to ignore United's away goal advantage. Real Madrid have to score in Manchester, and the onus remains on them to break down a United defence that has become increasingly resilient as the season has progressed.
For this reason, Ferguson will not be inclined to drastically change his approach from the first leg. United are expected to sit back and attempt to soak up Real pressure again before hitting their opponents on the counter-attack, using long diagonal balls to supply Danny Welbeck and Robin van Persie. At the Bernabeu this tactic came very close to snatching a second away goal in the closing stages and Ferguson will hope his team aren't made to pay for Van Persie's near misses.
"For them it was very tactical, but not for us," said Mourinho after the 1-1 draw on February 13. "They changed the way they play, I think, to have 11 men behind the ball and they did not put a foot in our half in the second half. They were just waiting for a set piece or a counter-attack."
Mourinho also tried to goad Ferguson into opening up and playing a more expansive game at Old Trafford. "Because of the English culture you can't play with defenders in your own box at home. United can't play like they did here," he added. "United didn't play to win but they did their job well."
Mourinho's transparent attempt to influence Ferguson's thinking is unlikely to persuade his counterpart, who will have seen the devastating effect to which Real Madrid can counter-attack against a team trying to take the initiative in their 3-1 victory over Barcelona at Camp Nou last week. But Ferguson will want his first XI to be more assertive in the opening stages as Real, and Cristiano Ronaldo in particular, pinned United to their penalty area in the first half-hour at the Santiago Bernabeu.
"The disappointing thing for me was that in the first half we sat off them," said Ferguson. "They got a lot of play on the edge of our box. It's not healthy that. It's not good to watch and it was unlike us."
Despite his incredible record at United, Ferguson is not renowned for being one of the game's greatest tacticians, with his two biggest challenges in recent years ending in failure. The manager's vaunted 'plan' ahead of the 2011 Champions League final did not materialise into any sort of threat as Barcelona eased to a 3-1 win, and negative tactics at the Etihad last season played a crucial role in Manchester City wrestling away the Premier League crown.
But in the first leg against Real Madrid, Ferguson and his backroom team readily adapted to the occasion, gaining a significant victory in one respect as Mourinho struggled to find ways to break United down. Mourinho's most significant in-game change was to switch Ronaldo and Angel Di Maria on the wings but while the Argentine was a menace in the second half, Ronaldo faded in a final 20 minutes in which the visitors created the better chances.
Ferguson, meanwhile, exhibited keen awareness to danger, pulling Welbeck back onto Xabi Alonso (more on this later) after the break. The manager will need to show similar eagerness to alter his set-up in the second leg, especially if Real take the lead.
Should this occur, we are likely to see Wayne Rooney push closer behind Van Persie, and as the game progresses
