The veteran shot-stopper started for the Gunners in their Premier League opener against the defending champions, but struggled with the ball at his feet.
Emery’s preference will be to continue playing out from the back and Leno, a £20 million summer arrival from Bayer Leverkusen, has the technical ability to better implement it than Cech.
However, speaking after the 2-0 defeat, Emery insisted the German international will have to be patient, suggesting the elder of the two will be his first choice until given a reason to change his mind.
‘Leno is starting with us, he is working very well and played very good in pre-season. He can wait [for] his moment,’ said the Arsenal boss.
‘Petr Cech is doing very good. Today he played good also. He has experience of defending our goal.’
Although Cech was not at error for either of the two goals he conceded against Pep Guardiola’s side, he struggled when asked with finding the right pass at the right moment.
In the first half, under pressure from Sergio Aguero, the Arsenal captain almost scored an own goal as he fluffed a pass and sent the ball skipping narrowly past the post and out for a corner.
Leno watched on from the bench while David Ospina, formerly Arsenal’s No 2, was not named in the matchday squad as he closes in on a move to Turkish outfit Besiktas.