Manager Scott Servais said the hope also was that by moving the game up, all the scheduled relievers will get their innings in as well.
"I got a text late last night saying we might have an issue," Servais said. "We just thought, 'Let's go ahead and get those innings in for those bullpen guys and get it rolling an hour early.' We should be fine, based on what I've heard. But we want to get the whole game in rather than cutting out after six or seven innings."
Left-hander Jason Vargas, a former Mariner, is scheduled to start for the Royals.
The Mariners' lineup for Monday's game:
1. Jarrod Dyson, LF
2. Jean Segura, SS
3. Kyle Seager, 3B
4. Danny Valencia, 1B
5. Mitch Haniger, RF
6. Mike Zunino, C
7. Taylor Moter, 2B
8. Tyler Marlette, DH
9. Leonys Martin, CF
Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.