Manchester United boss David Moyes is banking on their star strike-partnership to fire them to victory at Manchester City.
Robin van Persie and Wayne Rooney will start at the Etihad.
"If you are up against that partnership in the Premier League, you have a concern," says Moyes.
"There are some good centre-forwards in the League, but seeing Robin and Wayne up front gives defences a different dilemma. In form, they make it difficult to play against.
"I can tell the two of them are working on it. We want to try to make it a partnership where people say: "My goodness, this is tough to play against." If we can get them both scoring 20 goals this season, it will go a long way to deciding where we finish."