Jose Mourinho explains what Alexis Sanchez arrival means for Martial, Mata and Rashford at United

Jose Mourinho has reassured the likes of Marcus Rashford, Juan Mata and Anthony Martial they remain firmly part of his plans at Manchester United following the arrival of Alexis Sanchez – providing they step to the challenge at hand.

Ahead of the Chile international's potential debut against Yeovil Town in the FA Cup fourth round on Friday (26 January), there has been much speculation as to where Mourinho will choose to deploy his newest signing – and who could lose their place as a result.

Sanchez has been backed to slot in on the right of United's attack – a position where Juan Mata has started 17 times in the Premier League this season – alongside the club's two top goal scorers Romelu Lukaku and Anthony Martial.

By his own admission, however, Sanchez prefers a role down the left, where he excelled at Arsenal. Should Mourinho opt to name the Chilean in that position, it will intensify already heated competition with Martial and Marcus Rashford spending much of the 2017-18 season battling to become their manager's first-choice option down the left.

Mourinho has welcomed the added competition however, insisting Mata, Martial and Rashford along with first-choice centre forward Lukaku all have a responsibility to be prepared to deliver whenever called upon.

"This is life in big clubs," Mourinho told a press conference on Thursday when asked about increased competition among his attacking options. "At big clubs, you have big players, you have competition, you have responsibilities, you have to perform always, you have to try go to every competition in a serious way, you cannot do that with 11 players it is impossible.

"The players in big clubs know the squad is 20 something where everybody wants to play. What we cannot do is play 12 at the same time, start 12 in a certain match, but space for everybody and needed for everybody I think is absolutely fundamental."

Mourinho went onto praise the evolution of players like Martial before underlining the important of his front five – consisting of the France international, Rashford, Mata, Lukaku and Sanchez.

"It is a very important addition for us, now we have five attacking of high quality – Mata, Rashford, Lukaku, Martial, Alexis, and is fantastic for me and for the team. If the player one day are on the bench and don't like it, I am happy with that."