Deeney was dismissed just 12 minutes into the encounter, following an off-the-ball incident with the Uruguayan midfielder. He appeared to catch the ex-Sampdoria man with his elbow - just moments after Pierre-Emerick Aubameyang had given Arsenal the lead.
Ref Craig Pawson sent off Deeney after consulting his linesman.
Deeney would have words with the official, labelling the decision "a f****** embarrassment" before discussing the incident with Torreira.
On his way down the tunnel, Deeney removed his shirt and let the fourth official know his feelings on the situation.
He also directed his ire towards Emery, reports the Mirror, in particular voicing his disdain at Torreira.
Pointing back towards the field, Deeney declared: “He's a f****** p****.
“I've ran past him."