(Oakland, CA)  --  The Mariners promoted a pair from Triple-A Tacoma Tuesday, while designating another for assignment.  Right-hander Erik Swanson and utility man Kristopher Negron were promoted to Seattle while the team began the process of cutting ties with Mac Williamson.  The 29-year-old outfielder hit just .182 with three homers and 10 RBI in 25 games with Seattle.  The club leads the majors in players used this season with 53, as well as the most pitchers with 35 and relievers with 30.