Curtis was recalled from Double-A Arkansas on Thursday, Bob Dutton of The Tacoma News Tribune reports.
Curtis held a 3.21 ERA and 0.93 WHIP across 14 innings (10 games) with Double-A Arkansas before earning a promotion to the majors. The 24-year-old saw some time with the Diamondbacks in 2016, but he struggled to a 6.75 ERA and 10:13 K:BB through 13.1 innings (21 games), so he likely won't see anything other than low-leverage innings out of the Mariners' bullpen. Dan Altavilla was optioned to Triple-A Tacoma to clear room for Curtis.