Simon entered spring training as a candidate for both the rotation and bullpen, but he was slowed by a groin injury and allowed six runs and six hits over two innings upon his return on Wednesday in Dunedin.
Simon is likely to be claimed by another team because of his upper-90s fastball and versatility.
The Orioles need to clear room on their 40-man roster with the expected additions of catcher Ronny Paulino and first baseman Nick Johnson.
Executive vice president Dan Duquette wouldn't confirm Simon's placement on the waiver wire, saying that the waiver process is "confidential."
The Baltimore Sun first reported that Simon's name appeared on the waiver wire.