San Francisco 49ers running back Tevin Coleman's status for Sunday's Week 1 matchup vs. the Arizona Cardinals is uncertain due to concerns over the poor air quality in the Bay Area.

According to ESPN's Adam Schefter, Coleman's potential unavailability is “due to a combo of a pre-existing health condition” and the air quality. The decision on whether Coleman can go will lie with the tailback. Schefter's source said the situation remains “fluid.”

 

Wide swaths of Northern California and Oregon have dealt with alarming and dangerous air quality over the past week—a result of cascading climate change developments and the ongoing wildfires raging through California and the Pacific Northwest. The 49ers' home venue, Levi's Stadium, is located in Santa Clara, about an hour outside of San Francisco.

Coleman didn’t practice on Friday because of the air quality in Santa Clara. According to the San Francisco Chronicle, the 27-year old has the sickle cell trait, which renders him more sensitive to air pollution and low oxygen levels. 49ers head coach Kyle Shanahan said that if the air quality index reaches about 150, as it was during Friday's practice, Coleman would have a tough choice to make.

“It will be a personal decision when he gets there,” Shanahan said. “It’s similar to when you play in high altitude…It’s not an automatic no. It’s stuff you have to discuss with a doctor and be comfortable with.”

In 2016, Coleman faced a similar predicament as a member of the Atlanta Falcons ahead of a game at the Denver Broncos' Empower Field at Mile High. Despite suffering some breathing difficulties in the high altitude, Coleman ended up playing 26 snaps and recorded a career-high 132 receiving yards and a touchdown.

The NFL plans to go ahead with Sunday's Cardinals-49ers game, with kickoff scheduled for 1:25 PT, as long as the air quality index remains below 200.

Coleman is no. 2 on the 49ers' halfback depth chart behind Raheem Mostert. If Coleman is unable to play, Jerick McKinnon could see a few more snaps.