Villa lost the first-leg of their Europa Conference League semifinal 4-2 at home with Ollie Watkins and Moussa Diaby on the scoresheet.
Emery said: "We didn't play like we are playing and we need to keep being consistent.
Advertisement
Advertisement
"They deserved to win and they are a good team. It's not about luck. We didn't play well. We have to play better."
Villa captain John McGinn also admitted: "There were mistakes all round tonight and we'll take responsibility.
"We have a mountain to climb but we know we're capable. The manager was still positive in there.
"There's still a long way to go."