Cristiano Ronaldo
Crsitiano Ronaldo warmed up for the first-leg against Manchester United by striking a hat-trick against Sevilla. Reuters

Since Real Madrid and Manchester United were drawn together in the last-16 of the Champions League there has been a huge sense of anticipation about a meeting between arguably the world’s two biggest teams.

Leading the Premier League by 12 points, United are having a far better season that Madrid with Jose Mourinho’s side 16 points adrift in La Liga and resigned to relinquishing their title. Yet, having said that, it is Madrid that appear to have the strongest squad.

It is a tie that could go either way, so ahead of the first-leg on Wednesday here are six players who could be crucial to deciding which side progresses to the quarterfinals.

Cristiano Ronaldo
In any game he plays, Ronaldo’s talent and personality make him the focus of attention. But playing against his former club for the first time since his record move to Real Madrid, Ronaldo is set to be even more prevalent. The Portuguese forward could not have warmed up for the massive match any better than he did when scoring a fine hat-trick as Madrid cruised to a 4-1 win over Sevilla on Saturday.

His third goal showed why he embodies what Madrid’s key threat will be to United. Ronaldo picked up the ball just outside his own area before bursting upfield, shifting it to the right and continuing his run to receive a return pass for a simple tap in. In a blink of an eye, Ronaldo’s pace and drive with the ball could change the whole complexion of the tie.

Wayne Rooney
In the early days of Rooney’s time alongside Ronaldo at Old Trafford, it was the prodigal English forward who was undoubted top dog. But as Ronaldo blossomed into global superstar, Rooney was happy to take a back seat and fit his game around what was most needed for the team. It is a similar scenario that has developed since Robin van Persie arrived this season. The Dutchman is now the undoubted talisman at United, with Rooney providing the supporting role.

Rooney’s statistics continue to be highly impressive, but the moments where he takes your breath away and dominates a game as he did so often in his bustling youth have become few and far between. A clash with Real Madrid and Ronaldo presents the perfect opportunity for Rooney to show that he can shine on the biggest of stages.

Sami Khedira
For much of his time at Real Madrid, Khedira has been seen as a useful cog among a team of bigger stars, but this season the German midfielder has taken his game to another level. Khedira has proved that he is far more than a mere holding midfielder as he has impressed with his passing and also shown himself to be a threat in the opposition area.

A lack of dynamism in Manchester United’s midfield arguably remains their greatest weakness and Khedira could well be the man that most exploits it over the two legs.

Phil Jones
The versatile young Englishman is far from a first-choice for Manchester United and may well not even start, however, he has become the man for specific assignments for Sir Alex Ferguson. Jones, who has yet to establish his best position, was deployed in a right-sided defensive midfield role against Tottenham recently to try and mitigate the impact of Gareth Bale after the Welshman had ripped through United in their meeting earlier in the season. Jones was given a similar man-marking role at the weekend against Everton’s Marouane Fellaini, but it is was his successful job on Bale that most intrigues ahead of the clash with Madrid.

Although he is at this stage a superior player, Ronaldo operates in similar manner to Bale starting on the left but with ample license to come inside. Without Jones, there would be major concerns about Rafael at right back, protected by a potential central midfield partnership of Michael Carrick and Tom Cleverley. It would be a huge ask for the 20-year-old to marshal Ronaldo, but it could prove a tactical masterstroke.

Karim Benzema
At the age of 25, Benzema should be coming into his prime, yet there is still a sense that he has yet to fulfill the massive potential he showed at Lyon. The France international is an intelligent player and his movement and linkup play means his game should be judged on far more than just his strike rate, but just 13 goals at this stage of the season is still something of a disappointment.

Benzema looks likely to get the nod ahead of Gonzalo Higuain against United and he should be looking to terrorize a defense that has not always looked the strongest this season.

Robin van Persie
There were plenty of doubts raised when Sir Alex Ferguson decided to plash out £24 million on a 29-year-old with a history of injury problems. But as things stand the money looks like an extremely shrewd investment. Van Perise has struck 23 goals in just 31 appearances in his first season at Old Trafford and has taken United’s attacking play to a new level.

The former Arsenal man has demonstrated that he can be counted on to not only create chances for himself out of very little but to make the most of opportunities that fall his way. In what promises to be a finely balanced encounter with Madrid, that ruthlessness could be vital.