The concern is a result of the Northern California wildfires which have led to a total of 24 deaths as of Thursday afternoon. Countless others have been ordered to evacuate their homes.
The Raiders shifted the times of Thursday's practice session due to worsening air quality, according to Michael Gehlken of the Las Vegas Review-Journal.
An Air Quality Index value of 156 or higher is considered unhealthy, with Thursday's reading registering at 180.
As of Thursday, Sunday's game remains scheduled to be held in Oakland.