Arsenal have now won four matches in a row in all competitions after a slow start to Emery's tenure, but the Spaniard admits that his side could have done better on the night as Vorskla pulled back to within two goals.
Leno belatedly made his debut in last night's 4-2 win over Vorskla Poltava in the Europa League, but will nearly certainly return to the bench for Sunday's match against Everton.
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. He soldiered on after receiving some treatment but Emery chose to take him off shortly after we scored the third goal in the 57th minute.
Arsenal sit in seventh in the Premier League after three wins and two defeats, and face Everton at the weekend.
"My idea for each match is to arrive in the last hours to decide and say to the players my decision", he said.
Emery, though, said he does not need Aubameyang to carry the entire scoring burden for his team.
Oil prices fall amid surprise growth in U.S. crude stocks
He didn't however address how the global oil industry immediately can replace Iranian crude supplies in an already-tight market. Cementing that arrangement would be one of the topics of discussion as OPEC meets this Sunday in Algeria, he added.
We are going to continue thinking in each match about our best XI'.
'I have a lot of confidence in him, but also the other strikers like Danny Welbeck and Alexandre Lacazette. "It's clear, we want them to score".
"Each match we play, I am responsible for the group and for Torreira also".
He has been on the bench for the Gunners' first five Premier League games as coach Unai Emery has opted to stick with Cech as his No. 1 despite spending €25 million on Leno this summer.
"But now the [priority] for us is a good performance and we spoke with every player, and with this situation with the goalkeepers, [we spoke] to explain the situation at the moment and continue working for each match to give us the performance". I hope that tomorrow and Saturday, he will be okay for Sunday.