Moore's return will push Felix Hernandez back a day to Tuesday against the Royals, giving him an extra day of rest after this weekend's trio of Ariel Miranda, Sam Gaviglio and James Paxton take on the Angels.
With Drew Smyly officially done for the season as he faces Tommy John surgery and no timetable on Hisashi Iwakuma, whose return has been put on hold due to lingering shoulder issues, the Mariners appear settled on the current group while Yovani Gallardo continues to work out of the bullpen.
Having used 13 starters already this season, Servais is hopeful the merry-go-round can now stop and the rotation can get into a rhythm.
"I hope so. I say that and then we run into the All-Star break and all the guys will get a little breather at that point," he said. "But it does help, from a team standpoint, knowing what to expect when a guy takes the mound and getting in a rhythm as much as anything.
"We put a nice streak together that was driven by our offense, then we cooled off," Servais said. "But I've always said, when you put streaks together it's usually driven by starting pitching because they can keep you in games every night. Hopefully our guys will continue to do that going forward."
The Mariners re-set their rotation coming out of Thursday's off day, moving Miranda up to Friday's series opener and sliding Gaviglio back a day to Saturday. Servais said the idea there was to separate his two southpaws, with Gaviglio now between Miranda and Paxton in the rotation.
Moore, the Mariners' No. 4 rated prospect per MLBPipeline.com, won his Major League debut against the Tigers on June 22 when he allowed three runs on six hits over seven innings. The plan all along was to keep him pitching by sending him to Tacoma for one outing then bringing him back.
"We need another starter and he did a very good job last time he was here," said Servais.
Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB. This story was not subject to the approval of Major League Baseball or its clubs.