NASCAR sent a memo to teams earlier this week advising them to address “pockets of complacency” toward its COVID-19 mask protocols.
The memo was first reported by WCNC, NBC’s Charlotte affiliate.
In the memo, NASCAR said it was “seeing more and more van loads of crew members rolling up to the track without masks on, and people wearing their mask down around their chin.”
The memo stated that further flouting of the protocols “will threaten our ability to continue racing.”
“More people in our industry are going to contract the virus,” the memo added. “The key is limiting it.”
“It is important for everyone to do their part ALL THE TIME. One cluster outbreak can derail our season.”
In May, NASCAR issued a bulletin stating failure to comply with COVID-19 rules could result in a $50,000 fine.
The memo comes after seven-time champion Jimmie Johnson tested positive for COVID-19 last week, forcing him to miss the Brickyard 400. Earlier this week Johnson had two negative tests, allowing him to be cleared for Sunday’s race at Kentucky Speedway.
Previously, Stewart-Haas Racing had two employees test positive for virus and Team Penske had one employee test positive.
In North Carolina, where most NASCAR teams are based, the state now has 81,000 cases and it has reached 1,000 hospitalizations for the first time.
The Cup Series is scheduled to hold its All-Star Race on Wednesday at Bristol Motor Speedway in Northeast Tennessee. Tennessee has just over 59,000 confirmed cases and has had 86 deaths since Sunday, a single-week record.
NASCAR is scheduled to compete next weekend at Texas Motor Speedway. Texas has more than 235,000 cases and almost 3,000 deaths. On Thursday, it recorded 10,000 new daily cases for the second time.