Since a certain 35-year-old signed for Manchester United for free this summer, he has been starting alongside Wayne Rooney in the Premier League.

The Old Trafford side's attack hasn't been convincing this season as the Red Devils have scored only two goals in their last three games. Jose Mourinho doesn't seem to know who his team's best wingers are with the Portuguese selecting a new front-four every game. Yet two of them have been maintaining their starting positions in the side's attack.

In all of United's Premier League games so far Wayne Rooney has played as a number 10 behind the striker, Zlatan Ibrahimovic. The Swedish legend is a lethal attacker. He's one of few players who can change games. His supple body makes him one of the world's best strikers, but Ibrahimovic isn't a player who's constantly moving in all areas of the pitch, he isn't industrious. Therefore he needs a fast, pacey playmaker behind him.

Slowing up the play

The England captain is slowly becoming a slower player. He's not as fast as he used to be and Rooney's recent performances puts questions on his position in the starting line up. Is the 30-year-old the right player to help Ibrahimovic contribute and score? The answer seems to be no.

In an attacking duo, at least one of the elements has to be energetic. Ibrahimovic and Rooney form an extremely slow partnership at Manchester United, a club who are famous for it's fast flowing attacking football under Sir Alex Ferguson. The presence of Juan Mata on the right doesn't help either, as the Spaniard is not a speedy winger.

Sticking to his promise

Jose Mourinho promised his supporters that he'll keep the club's historical identity by bringing back attacking football in August. In order for that to happen, the Portuguese must keep Rooney away from the starting line up and replace him with a fast, creative midfielder. With Mourinho stating that the current captain won't play as a central midfielder under him in his first press conference at the club, there is doubt over whether or not another position is available for the Englishman to fill.

The boss can also change the team's formation and style of play, which also requires sacrificing Rooney. But one thing's for sure, both can't be on the pitch at the same time.