I'll talk you out of it.
Felix is going to pitch awesome. You will be amazed at how skilled of a pitcher he is. By the 5th inning when the score is still 0-0 you are going to start getting nervous that the Mariners will not have scored any runs. In the 7th inning Felix will start to get tired and give up one run. In the 8th inning the Mariners will go to its bullpen and implode.
If you enjoy watching a very painful team to bet on and enjoy the frustration of watching a great pitching performance go down the drain - by all means bet the M's.