Perez joined the Gunners from Deportivo in a £17m deal last summer
He did, however, score when given opportunities in the FA Cup and Champions League, contributing six goals in 10 games in those competitions.
During the summer, Perez saw his number nine jersey handed to new signing Alexandre Lacazette, seemingly signalling that he had been deemed surplus to requirements.
After something of a journeyman existence earlier in his career, Perez had been prolific during the 2015/16 season with Deportivo. He netted 17 times in 36 La Liga games and was the fourth highest Spanish scorer in the division behind only Aritz Aduriz, Ruben Castro and Borja Baston.
Arsenal have wished the 28-year-old luck on his loan.
A statement read, "We all wish Lucas well for his time with Deportivo this coming season."