The Mariners optioned Vargas to Triple-A Tacoma on Thursday, Shannon Drayer of Seattle Sports 710 AM reports.
Vargas allowed three earned runs in 5.1 innings across six spring training games, and he will ultimately miss out on a spot in the Mariners' Opening Day bullpen. The 24-year-old righty turned in a 7.23 ERA and 2.11 WHIP across 42.1 innings with Arizona's Triple-A affiliate last season, and he will certainly need to improve upon those numbers before he gets called up to Seattle.