Yacabonis' contract was selected by the Mariners on Saturday.
Yacabonis rejoined the Mariners on a minor-league deal during the offseason, but he began the 2021 campaign at Triple-A Tacoma. The right-hander was effective across 24 appearances (one start) in the minors with a 1.72 ERA and 1.03 WHIP in 31.1 innings, and he'll now join Seattle's bullpen as a low-leverage reliever.