Manchester United may not be the force of seasons gone by, but tomorrow's match against rivals Liverpool is still one of the most eagerly anticipated of the campaign.

The Premier League title is out of reach, but United still have slim aspirations of finishing in the top four, while the visiting Reds need to claim all three points at Old Trafford to maintain their pursuit of leaders Chelsea.

Much has been made of which players David Moyes and Brendan Rodgers should include in their respective starting lineups and here, Sports Mole has picked out three from both teams who could have key roles.

Man United

Phil Jones
With captain Nemanja Vidic bound for Inter Milan, Chris Smalling and Jones were given the chance to show that they can replace the Serbian during last week's 3-0 win at West Bromwich Albion. While Smalling put in an accomplished performance, Jones, only just returning from injury, at times looked rusty up against the physical presence of Victor Anichebe.

Nevertheless, the 22-year-old is highly thought of at United, so much so that last season Sir Alex Ferguson insisted that he had the potential to be one of the club's greatest ever players. Many scoffed at that suggestion, but up against the in-form Luis Suarez and Daniel Sturridge, Jones has the opportunity to prove his former manager to be correct.

Marouane Fellaini
If truth be told, then the Belgian has struggled to adapt to life as a United player since his £28m move from Everton back in early September. His displays have been scrutinised, while injuries and a red card against Real Socieded have limited his contribution.

However, against Crystal Palace last month and more recently during the encounter with West Brom, Fellaini showed signs of improvement. He completed more passes than any other Premier League player last weekend, while he also displayed good awareness to make a host of clearances. He may still have plenty more to do to convince the doubters that he has the necessary quality to play for United, but another positive showing against Liverpool will do him no harm. Assuming that he takes up a holding role, he will be charged with the task of nullifying Philippe Coutinho's threat, as well as getting forward whenever possible.

Robin van Persie
The Dutch striker recently stressed that he is happy to remain a United player despite speculation to the contrary, but now supporters will want him to show that commitment on the pitch. Since returning from a thigh injury in January, Van Persie has scored a respectable four goals in seven outings, but it's been his body language and attitude that have been called into question.

What's more, his partnership with Wayne Rooney has come under the microscope. A host of statistics have been brandished regarding the number of times that the pair have passed to each other, although Rooney has stressed that they are both working hard on developing their understanding.

Liverpool

Daniel Agger
Many pundits have argued that Liverpool's frailty in defence is what will ultimately hamper their quest for a first league title in 24 years. Indeed, while Chelsea and Arsenal have shipped 22 and 28 goals respectively, Rodgers's team have conceded 35.

At times this season, though, Rodgers has had to get by without the services of Danish international Agger, which has resulted in the likes of the calamitous Kolo Toure partnering Martin Skrtel at the heart of the rearguard. Agger is now fully fit and has shown in outings of late that he is best suited to be playing alongside the Slovakian. While Skrtel provides the brawn, Agger is more assured in possession, which allows him to start attacks from the back.

Steven Gerrard
No longer a 90-minute box-to-box midfielder, Gerrard has inherited a more reserved role in the Liverpool midfield this term. It's paying dividends as well, highlighted by the fact that he has laid on nine Premier League assists, adding eight goals of his own in the process.

Against United, Gerrard will have the responsibility to set Liverpool's tempo. It will also be vital that he does shirk his role without the ball, particularly because the hosts may deploy an attacking trio of Rooney, Juan Mata and Adnan Januzaj behind lone frontman Van Persie. Along with Jordan Henderson and Joe Allen, it will be crucial that those three United players are not given too much time in possession.

Luis Suarez
By the standards that he has set himself, the Uruguayan has been a touch off-colour in terms of goals in recent weeks. Liverpool may have been free-scoring, but Suarez has fired in just one goal in his last six appearances. Having said that, his performance levels have not dropped, particularly when it has come to creating opportunities for Sturridge et al.

The trip to United will also be a test of Suarez's character. He is used to being jeered by opposition supporters, but the noise levels against him will probably rise tenfold, largely because the 27-year-old was found guilty and suspended for racially abusing United full-back Patrice Evra during an incident at Anfield in 2011. It's rare that Suarez is affected by a negative reaction to his presence and it will be important that he continues to show the same mentality against the Red Devils.