Jhon Duran struck for the 1-0 win on Saturday.
Emery later said, "We won and that's positive but the difficulties we had were in our expectation. Over the 90 minutes we had chances to score more goals but sometimes they were dominating possession. Today we managed the game plan more or less to try and find the way to win.
"It's important for the team. Today we had chances. We dominated sometimes both boxes. At the beginning for sure but the second half they didn't get to our box,. We had chances to score the second goal which we didn't do. Amazing goal from Jhon Duran, individual brilliant goal his ability to run in behind and he's very clinical.
"The most important thing is how we are progressively getting comfortable on the field. We have to try to use substitutions because we have Champions League on Tuesday. Three matches in nine days. We have to be ready with the players we have available to try and enjoy the competition."
He added: "Each step we have to try to get comfortable. We are fighting with Brentford, Nottingham Forest, Newcastle, Brighton and we have to try to be there. We focus on the next match, Champions League and then the match against Forest."