Curtis pitched a scoreless two-thirds of an inning in Friday's 4-0 loss to the Blue Jays.
The 24-year-old southpaw now has 1.2 scoreless innings to his credit since being called up from Double-A Arkansas on Thursday. Curtis had posted a 3.21 ERA, 0.93 WHIP and 13:4 K:BB over 14 innings across 10 appearances in the minors before arriving in Seattle, and could see his role expand as he increasingly gains the trust of manager Scott Servais.