Less than 24 hours after unloading four minor leaguers for some bullpen help, Mariners GM Jerry DiPoto swapped the club's top prospect to add an arm to their oft-injured rotation.

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In a deal with the St. Louis Cardinals, Seattle sent OF Tyler O'Neill to the NL in exchange for lefty starter Marco Gonzales. Gonzales, a Gonzaga alum, missed the entire 2016 season after undergoing elbow surgery and has pitched in just one game thus far this year.

The Mariners dropped the opener of a four-game series against the New York Yankees last night by a 4-1 tally, despite a glowing performance by ace Felix Hernandez.