There was a time when it appeared that Manchester City's Sergio Agüero and Manchester United's Robin Van Persie were competing for the Premier League's striking crown.
The two forwards will go down in history as two of the best ever front men to play in England's top-flight, although Van Persie's struggles this campaign are summed up by how far he has slipped behind Agüero.
|Goals||Shots per game||% of shots on target||Dribbles won||Touches||Passing accuracy||Mins Played|
|Robin van Persie||3||2.5||55%||4||262||85.3%||676|
The Dutchman has struggled to find his top form, despite Van Gaal's persistence with him, and only has three goals to his name so far.
that total is dwarfed by Agüero, who, in considerably fewer minutes, has already clocked up nine goals for the season and is joint-top of the Premier League scoring charts with Diego Costa.
The Argentine, when fit, is arguably the biggest threat in the country and United will have to be on top form to deny him from getting on the scoresheet this Sunday.
Agüero has proven to be a problem for every defence he has played against so far this season and this is because of his willingness to shoot - although United could learn from West Ham, who stopped him from scoring.
The former Atletico Madrid man is averaging nearly five shots in every game he plays, with over 50% of these hitting the target. By comparison, Van Persie has only taken half that amount of attempts and, although he has shown his finishing ability with most of them hitting the target, that simply isn't enough for him to hit the heights he previously has in his career.
The 31-year-old is starting to show signs of age and just isn't as involved as Agüero has been, with the City striker taking more runs at defenders and linking up with his teammates more often. The two will be in direct comparison this weekend and Van Persie will need to show a serious up-turn in form if he is to help his side to victory.
City's defence has been exposed previously this season but the United forward will need to be back to his predatory best if he is to take advantage of this and aid the Red Devils as they look to claim a huge three points.
A Sky Sports News poll asked which striker is better earlier today and the vote was tied at 50-50. But who will come out on top on Sunday?