Torreira is now a key member of the Gunners.
Unai Emery says he slowly introduced Lucas Torreira into the Arsenal first team because it's always key to "respect hierarchies".
The 22-year-old midfield marshall joined the Gunners from Sampdoria in the summer transfer window after his fantastic display with Uruguay at the World Cup in Russia.
However, speaking to Marca, the former Sevilla and PSG boss said: "Because you have to respect hierarchies.
"If [Benrd] Leno comes as a signing, but [Petr] Cech is doing well, we have to respect him. Petr was first. And the same happened with [Matteo] Guendouzi and Torreira, who arrived later.
"I kept the first one, which I love, although now I do not play, and yes Lucas."