SEATTLE — Let the arms race begin.
At least, the race for relievers.
The New York Yankees and Seattle Mariners, who are in the midst of a four-game series at Safeco Field, have taken the first shots.
The Yankees acquired right-handed relievers David Robertson and Tommy Kahnle, as well as two-time All-Star third baseman Todd Frazier, on Tuesday night from the Chicago White Sox in exchange for reliever Tyler Clippard and three prospects.
The Mariners, who are chasing the Yankees for an American League wild-card berth, countered Thursday by getting reliever David Phelps from the Miami Marlins for four prospects: outfielder Brayan Hernandez and right-handed pitchers Pablo Lopez, Brandon Miller and Lukas Schiraldi.