Both clubs are reportedly expect to reschedule the postponed games in San Francisco this week.
Tuesday night's Giants-Mariners game that was scheduled to take place in Seattle has been postponed due to air quality concerns, according to NBC Sports Bay Area's Alex Pavlovic.
The clubs were supposed to play a two-game set in Seattle, however, they are now expected to both fly to San Francisco and play either a doubleheader on Wednesday or single games on Wednesday and Thursday, when both are off, according to NBC Sports Bay Area.
Following a wave of massive wildfires on the west coast of the United States, some cities in the region have some of the worst air quality in the world as of Tuesday evening.
According to IQAir, a group that tracks global air quality, Portland, Seattle, Vancouver and Los Angeles all have the worst air quality in the world as of Tuesday evening. Portland's AQI Index is at 271, which is said to be very unhealthy. Both Seattle and Los Angeles have AQI readings in the "unhealthy" range.
San Francisco, which had air quality issues throughout much of last week, has an AQI forecast of "moderate" as of Tuesday evening.
According to ESPN's Jeff Passan, MLB officials are also starting to consider how the west coast fires will impact the MLB postseason, particularly the ALDS and ALCS, which are scheduled to take place in California. Per ESPN, while no plan has been finalized, Phoenix has emerged as a backup site if the league needs to move any of its postseason games on account of air quality concerns.
The Giants are currently 23–24 and in third place in the NL West. The Mariners are 22–26 and in third place in the AL West.