The Colorado Rockies selected the contract of Jorge Alfaro and optioned fellow catcher Brian Serven to Triple-A Albuquerque on Thursday.
The Rockies also designated right-hander Blair Calvo for assignment.
Alfaro, 30, signed a minor league deal with the Rockies on Saturday a week after being released by the Boston Red Sox. He's yet to play in a big league game this season after playing in parts of seven seasons for the Philadelphia Phillies (2016-18), Miami Marlins (2019-21) and San Diego Padres (2022).
Alfaro is a career .256 hitter with 47 home runs and 194 RBIs over 478 games. In 46 games between Boston's and Colorado's Triple-A affiliates this season, he's batted .323 with seven homers and 33 RBIs in 46 games.
Serven, 28, played in 11 games for the Rockies this season, his second with the big-league club. He was batting .130 with one double and one RBI while making two errors in those 11 games.
Calvo, 27, made his major league debut May 30 for Colorado and pitched a 1-2-3 inning at the end of a loss to Arizona.