The two teams battled it out in a hotly contested friendly in the United States, which the German side won 2-0.
After they locked horns in New Jersey, Emery spoke about the need to play quality opposition before the Premier League begins.
“We are in preseason and practicing with the team and progressively getting better,” Emery said.
“Today was a match against an opponent of the level we will face in the season. It was a test.
“In the first half I think we were good, even losing 2-0 due to two mistakes. One goal was a clear offside.
“We are trying to contest with ourselves some tactical work and after the red card it was a completely different match.
“The idea after it was to get the work we did with players like Jacob Ramsey and Emi Buendia taking minutes.”