The new Gunners head coach has faced some criticism following Sunday's 2-0 loss to Manchester City - including from Sam Allardyce and club legend Tony Adams, who questioned his tactics in wake of the defeat.
Arsenal signed Leno for £22m from Bayer Leverkusen in the summer but the German will have to bide his time while Cech keeps his place between the sticks. He has experience, he has quality, he has the capacity.More news: Liverpool’s third goal v West Ham was clearly offside, says Manuel Pellegrini
"For Saturday, the decision for me is easy. I want us to continue with this work and to be competitive for 90 minutes, but with a better performance than on Sunday".
"The fans have been waiting for many years for a top quality, experienced central midfielder but against Man City, they started a 19-year-old from the French second division. Whether that means he's got the players already or he's going to have to bring them in throughout three or maybe four transfer windows, I believe he should get that and we should judge him then".
The 36-year-old appeared to struggle with Emery's new approach of playing the ball out from defence in Sunday's season opener, nearly scoring an own goal in the 2-0 defeat as he looked uncomfortable in possession.More news: Flash Flood Watch In Effect For Most Of Maryland
"We want a good preparation before and a good response on the pitch to that preparation".
"We didn't lose because of our personality, our idea, our style". Whether we can do one midfielder more either more attacking or more defensive, it depends'.
However, Nacho Monreal should be ready to start after taking part in full training all week, while Emery said continuing with right-back Stephan Lichtsteiner - who replaced Maitland-Niles - is also an option.More news: Pedestrians injured in crash outside parliament in London
Speaking on Sky Sports show The Debate, Rosenior said: "Emery's probably spoken to the directors and said this is the way I play".