Bass signed a big-league contract with the Mariners and will be available for Tuesday's game against the Rangers.
He was released from his minor-league deal with the Reds after exercising his opt-out clause, and the Mariners were there to swoop in and bring him on via a big-league deal. The 31-year-old journeyman logged an International League-high nine saves while posting a 2.21 ERA and 19:6 K:BB in 20.1 innings before the Reds let him go. Bass should pitch in mid-to-low-leverage innings for Seattle going forward.