Uruguay national Lucas
The Arsenal midfielder was given a straight red in stoppage time during Saturday’s north London derby, which ended in a 1-1 draw, for a challenge on Tottenham left-back Danny Rose.
As a result, he will miss Arsenal’s next three Premier League games against Manchester United (h), Newcastle (h) and Everton (a).
Torreira will, however, be available for Arsenal’s Europa League last-16 first leg against French club Rennes on Thursday.
Arsenal will however miss Torreira when they host United on Sunday, in a crucial match in the race for the top four.
After narrowly failing to beat Tottenham on Saturday, Arsenal moved out of the Champions League qualification places and are one point behind United.
However, United are also missing key players ahead of Sunday’s game at the Emirates, with nine senior players currently out injured.