The Rockies selected Romo's contract from Triple-A Albuquerque on Friday.
The switch-hitting Romo earned his first big-league promotion after hitting .297/.339/.499 with 14 home runs and three stolen bases over 85 games this season with Albuquerque. He and Jacob Stallings will form the Rockies' catching duo down the stretch following the release of Elias Diaz.