CHARLOTTE, N.C.

NASCAR has fined Tony Stewart $35,000 for criticizing the series about a potential safety hazard during races.

The fine issued Thursday falls under NASCAR’s new behavioral policy and comes a day after the three-time champion warned that a driver is going to get hurt if the series doesn’t start policing pit stops for missing lug nuts.

There’s been a rash of loose wheels the last two races because some teams are not applying the maximum five lug nuts during pit stops. By skipping one or more, a team can have a faster stop and gain better track position.

Loose wheels can create accidents or cause a tire to fall off a car. NASCAR stopped officiating missing lug nuts last year.

Stewart has been cleared to return to racing and will be back in his car Friday at Richmond International Raceway.

The three-time NASCAR champion missed the first eight races of the season with a fractured vertebra suffered in a January all-terrain vehicle accident. The injury occurred one week before Stewart was scheduled to start his final season in NASCAR. He’s retiring at the end of this year.

“As soon as the doctors said they were happy with my scans, I wasn’t going to wait any longer to get back in my race car,” Stewart said, announcing his return Thursday on Twitter. “I want to make the most of my last season in Sprint Cup, and I’ve been on the sidelines long enough.”

After Sunday’s race at Richmond, Stewart will participate in a Goodyear tire test at Indianapolis Motor Speedway. He plans to qualify and start his car at Talladega Superspeedway in Alabama, but he will give his seat up after the race begins to Ty Dillon. Stewart says the style of racing at Talladega could lead to an accident that could hurt his comeback.

“We’re taking a strategic approach to my return,” Stewart said. “Richmond is a track where I feel very comfortable and because it’s a short track, the speeds are substantially less. The Goodyear test in Indy is sort of a controlled environment, allowing me to get more acclimated with my car at higher speeds. We’ll start the Talladega race to get the points, but understanding the style of racing and the higher potential of getting involved in an incident, we thought it was best to minimize the amount of time I’m in the car.”

He plans to return to full-time racing at Kansas the following week.

Stewart thanked fans for their support and said “the best medicine will come this weekend at Richmond when I finally get to go racing.”