Poreda was optioned to Triple-A Charlotte following Tuesday's game against the Rays to make room for Carlos Torres, who is filling in for the injured John Danks.
Poreda was 1-0 with a 2.45 ERA in 10 relief appearances for the White Sox. He struck out 12 batters and walked eight in 11 innings.
"Poreda didn't get sent down because of his performance," manager Ozzie Guillen said. "He got sent down because we need to [send him down]. He got sent down because he wasn't used that much. He will be back in the big leagues soon.
"Now he knows what the big leagues are and knows what to expect. He's got to throw the way he does and he will be here soon."
Poreda was used out of the bullpen despite being groomed as a starter in the organization. While in Charlotte, Guillen believes Poreda will continue to be used out of the bullpen, since that is where he will be needed again upon his return.
"I think he should be in the bullpen because with the starting rotation we have, I don't think he's going to be a starter for us right now," Guillen said.
David Just is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.