BALTIMORE - The Seattle Mariners bolstered their depth behind the plate, acquiring catcher Welington Castillo from the Chicago Cubs for right-handed relief pitcher Yoervis Medina.
Castillo will back up Mike Zunino, who brought a .179 batting average into Tuesday night's game against the Orioles.
"With the number of catchers that go down in a season, if anything were to happen to Zunino and he went down, I'm not sure we would have had the depth to take his place," Mariners manager Lloyd McClendon said.
Castillo appeared in 24 games with the Cubs this season, including eight starts, as one of two backups to Miguel Montero. He played parts of six seasons with the Cubs, appearing in 223 games during the 2013 and 2014 seasons.
Castillo is a .252 hitter with 29 home runs and 110 RBIs in 310 career games, all with the Cubs.
"His playing time will be predicated on Zunino's performance," McClendon said. "Mike Zunino is our catcher."
Medina will report to Triple-A Iowa with the Cubs organization.
Medina was 1-0 with a 3.00 ERA in 12 relief appearances with Seattle before being optioned to Triple-A Tacoma on May 3. Medina has made 141 relief appearances with the Mariners the past three seasons.