Emery is confident they can handle this season's busy schedule, which includes a Champions League run.
"The players have to be ready to play in whatever competition we are playing," Emery said. "Right now we are more or less repeating the same XI, but the season is going to be long and we are going to play a lot of matches. We are going to have injuries, like we do now with John McGinn and before with Jaden, with Cash - he is coming back next week as well.
"I think the players are evolving in our structure and understanding the process for the year, how it is coming. For example, Ross Barkley has been high impact but his adaptation is going well.
"He is not playing in the starting XI in Premier League matches but I believe in case he will play on Sunday or on Wednesday against Bayern Munich he is close to understanding everything tactically I want. In training sessions he is really performing well.
"Hopefully we can get our new players understanding our tactical idea. Kosta (Nedeljkovic) is another example. Hopefully we can get our new players understanding our tactical idea as soon as possible."