Rumbelow was traded to the Mariners in exchange for minor-league pitchers JP Sears and Juan Then, Ryan Divish of The Seattle Times reports.
Rumbelow, who was recently added to the Yankees' 40-man roster to protect him from the Rule 5 draft, spent all of last season in the minors after missing almost all of 2016 due to Tommy John surgery. The 26-year-old split time between Double-A Trenton and Triple-A Scranton/Wilkes-Barre, posting a combined 1.12 ERA and 0.80 WHIP across 40.1 innings. He's looking to make it back to the majors for the first time since 2015 -- when he compiled a 4.02 ERA and 15 strikeouts in 15.2 innings with the Yankees -- and should have a clearer path in Seattle.