"Bernd Leno says he is ready to build on his Arsenal debut and push to become first-choice goalkeeper after a" frustrating" start to life at the club.
Thursday night's Europa League win over Vorskla extended the Gunners' winning run to four matches and they couldn't have asked for a much kinder Premier League fixture on Sunday as Everton travel to an Emirates Stadium that has traditionally been their bogey ground.
"It was disappointing to see the two goals go in because there was progress in the 90 minutes", said Emery.
"And for Leno... I think that we conceded two goals but not for a mistake".
"I want to create memories here, I want to win things with this team, and to do that we have to have belief in our ability to beat the best teams".
The North London club were marching towards a dominant victory on Thursday when Mesut Ozil put them 4-0 ahead but two goals in the last 14 minutes from the visitors left Arsenal without a clean sheet this season.
Aubameyang enjoyed a restorative showing after only finding the net once during the first five Premier League games of the season, but the former Borussia Dortmund star was frustrated by his team-mates' late lapses.
The Uruguayan worldwide was heavily involved against Vorskla as he dictated play from the deep-lying midfield role and helped Arsenal ease in to a commanding 3-0 lead thanks to a Danny Welbeck header and a sublime double from Pierre-Emerick Aubameyang. We are speaking before each match to take a mentality of don't concede easy chances. We want to play because we have the players to play from the back to have more space in the opposite 18-yard box.
Each match we play, I am responsible for the group and for Torreira also, today I think it is better [for Lucas] to leave the match.
"But we need to improve and fight to not concede goals like we did in the last few minutes".
"I think it could change, not every week, but he will change a lot".