Nuno started four games after J.A. Happ was traded to the Pirates on July 31, going 0-1 with a 4.58 ERA after posting a 2.02 ERA in 21 relief appearances this year.
The Mariners had Elias in the bullpen the past week to help fill the void created by veteran Joe Beimel going on the disabled list. With Charlie Furbush also on the DL, the only lefty relief candidates were rookies Edgar Olmos, Rob Rasmussen and David Rollins.
Nuno, who last started on Sunday, needed time to recover from that 6 2/3-inning outing before he could be available to help in the bullpen.