Reyes' request is a blow to new Atletico boss Diego Simeone, who replaced the sacked Gregorio Manzano last month and wanted to include the forward in his plans.
"Sevilla are giving me the chance to return home," Reyes told AS.
"It's an option I have on the table which might never come along again and I want to make the most of it.
"They operated on my father a few weeks ago and the best thing for everyone is to go back.
"I always wanted to return to Sevilla, it's an exciting goal for me to return to the team that gave me the chance to become a professional."