The Orioles made the moves before Tuesday night's game at Kansas City.
Clevenger left the team after the series opener Monday night to be with his wife, who was due to be induced. Peyton Lee Clevenger was born Tuesday afternoon.
Janish has played parts of six big league seasons with Cincinnati and Atlanta. He hit .235 with 21 RBIs in 95 minor league games this season.
To clear space on the 40-man roster, the Orioles outrighted knuckleballer Eddie Gamboa to Norfolk. He had been designated for assignment and cleared waivers.