Wesley Daniel, 24, was injured Monday while practicing the stunt, which somehow went awry.
Stagehands with fire extinguishers put out the flames and Daniel was transported to Loyola University Medical Center in Maywood, Ill., where he remained Wednesday.
Despite the burns, no damage was done to his lungs or trachea, and he is expected to be released by Thursday, the Tribune said.
The fire-spitting stunt has since been dropped from Lyric Opera's production of Richard Wagner's "Die Meistersinger von Nurnberg."
"I only have second degree burns so my face should be just fine," Daniel wrote on Facebook Tuesday. "If not, my next show will be 'The Phantom of the Opera.' Thank you everyone soooooo much for your thoughts and prayers. I am the luckiest hideously deformed person in the world, but in all seriousness I am truly blessed to have all of you in my life."