The Mariners acquired Biddle and Arodys Vizcaino (shoulder) from the Braves on Monday in exchange for Anthony Swarzak and cash, Greg Johns of MLB.com reports.
The Braves recently cast Biddle off their 40-man roster by designating him for assignment, but he'll stick in the big leagues as he moves on to a new organization in Seattle, according to Corey Brock of The Athletic. With 10 walks issued over 11.2 innings this season, Biddle has struggled with his control and may be limited to low-leverage relief duty with Seattle until he proves he can find the strike zone with more consistency.