The Seattle Mariners are the only team to have never played in the World Series. Established in 1977, the Mariners have just six playoff appearances and two ALCS appearances, once in 1995 and another in 2001. Seattle became the final team to never make a World Series in 2007, when the Rockies made their first appearance.

The Mariners won Game 1 of the AL Championship Series over the Toronto Blue Jays, just two nights after Friday's 15-inning epic win back home over the Tigers in a winner-take-all Game 5 of the ALDS.