Emery has given Torreira videos of his finest Arsenal performances in a bid to help the midfielder rediscover his best form.
"I showed him some movies about his best performances with us and how he can improve," Emery said.
"He started playing in the Premier League last year and he progressed, but this year again he needs to progress.
"He is a very good player, important for us, and his focus needs to be with us 100 per cent. His response to me was positive.
"He has a very big future here but thinking he needs to improve. He has to learn in some situations, individually to help us, to do better. It's one process.
"But really at the moment he was playing good last year, this year he's not being consistent but my challenge to him is to improve, to do better with some tactical issues on the pitch but above all being consistent."
When the Arsenal boss was questioned about Torreira's change in position, he suggested the 23-year-old had work to do before he could again be trusted with the 'big responsibility' of being their principal holding midfielder.
"He needs to achieve confidence, achieve more matches and more experience to take that confidence to do that.
"He can play as a defensive midfielder but we need a defensive midfielder (to be) offensive because to build up for us is very important. At the moment he is in that process.
"He can learn and improve but needs time."
He added: "He's helping us, he's sometimes playing well, he's being consistent but needs I think to learn or improve in that issue... we need him with his behaviour and his commitment playing in the position we are using him.
"Then when his process is better or taking more experience, he can take more responsibility."