Pep Guardiola has claimed Sergio Aguero and Gabriel Jesus cannot play alongside each other until Benjamin Mendy returns from injury.

The Manchester City manager insisted the choice between the pair is now his hardest decision, with one set to miss out each game.

Mendy is not back from an ACL injury until April and Guardiola revealed the left back's ability going forward dictated that his star strikers could line up together.

Manchester City boss Pep Guardiola has conceded he is facing the 'toughest decision'

Guardiola said Gabriel Jesus and Sergio Aguero cannot be paired until Benjamin Mendy is back

'Both have different qualities - they deserve to play,' Guardiola said. 'They have a lot of games and they have to be ready. It is the toughest decision.'

Asked if they could play together, he added: 'Yeah in the moment we had Mendy. When you have Mendy, he can play wide and the winger can go inside.

'Fabian Delph cannot do that. Without Mendy, Leroy Sane has to go wide, which is why they don't play together.

'Sergio after the crash, he was fit. He is fit. For me he is so tough. So is Gabriel.'

He explained that Mendy allows wide players to move inside but stand-in left back Fabian Delph (right, in action during the victory at Leicester last Saturday) 'cannot do that'

Mendy will not return for City until April, having sustained a serious injury to his ACL

The French international picked up the injury in the win against Crystal Palace in September

Guardiola also suggested teenagers Phil Foden and Brahim Diaz are ready for full debuts - although did not say whether either will be handed a start against Feyenoord on Tuesday night.

City will ring the changes after already qualifying for the Champions League last-16 and Guardiola said: 'They are two young players training this season. What I saw in the pre-season, the training, the World Cup, they are ready.

'Here in the high level we try and help the young players. They've shown me the same we saw when they played in the second and third team. The skills and quality are there.

'We can help them with speed because the lack of time is higher so Phil has to fight duels against Kevin De Bruyne, against Fernandinho, against David Silva. Every day is a step to improve.

'Years ago, people had more time to think. Now it is reduced. Everything is quicker. The players are faster in all senses, physically and mentally. I said in pre-season, those guys will train with us all season. They have to be ready. Sometimes the manager makes a surprise.'