Kurt Busch will miss the Daytona 500, and finds himself once again fighting for his career.

Busch was suspended by NASCAR indefinitely Friday after a judge said the 2004 former champion almost surely choked and beat a former girlfriend last fall and there was a "substantial likelihood" of more domestic violence from him in the future.

The suspension came two days before the season-opening Daytona 500, and Busch immediately said he'd appeal.

Although an appeal can be heard as early as Saturday, Stewart-Haas Racing has already decided to use Regan Smith in the Daytona 500.

The move to Smith by SHR, perhaps spurred by Chevrolet's decision to suspend its affiliation with Busch on Friday, is a blow to the Busch camp.

"We ask everyone's patience as this case continues in the court of law and are confident that when the truth is known Mr. Busch will be fully vindicated and back in the driver's seat," Busch attorney Rusty Hardin said in a statement, adding the assault allegation has led to "a travesty of justice" that will become clear as Busch continues to defend himself.

Busch is the first driver suspended by NASCAR for domestic violence. Chairman Brian France had maintained the series would let the process play out before ruling on Busch's eligibility — and the series came down hard in finding that he committed actions detrimental to stock car racing and broke the series' behavioral rules.

Travis Kvapil, who qualified second for Friday night's Truck Series race, was arrested and charged with assault of his wife in 2013. NASCAR took no action against Kvapil.

But it's a different time in sports since former Baltimore Ravens running back Ray Rice's own case of domestic violence forced leagues to take a harsh stance against participants accused of assault.

After the suspension was announced, on the glass outside of Busch's garage stall at Daytona, someone had scrawled in black marker "#41 Ray Rice." Busch drives the No. 41 Chevrolet.

In a 25-page opinion explaining why he issued the no-contact order this week, Family Court Commissioner David Jones of Delaware concluded that it was more likely than not that Busch abused Patricia Driscoll by "manually strangling" her and smashing her head into a wall inside his motorhome at Dover International Speedway last September.

The 36-year-old Busch has denied the alleged assault, which is the subject of a separate criminal investigation, but the judge said Driscoll's version of the incident was more credible than Busch's.

Driscoll said she was never motivated to have Busch punished by NASCAR.

"I reported a crime, just like anybody else who has been abused should do, because no one is above the law," Driscoll said. "I'm very encouraged that NASCAR is taking steps to recognize that domestic violence is a serious issue, and I hope that we see them develop a very clear policy on it."

It is Busch's third career suspension. He was suspended in 2012 by NASCAR for threatening a reporter, and parked for the final two races of the 2005 season by Roush-Fenway Racing after he was pulled over by police in Arizona.

He now races for SHR. Busch has 25 career wins but only one since 2011. It came last year, his first season with SHR, the team that helped resurrect his career.

Team co-owner Gene Haas hand-picked Busch to drive a car paid for out of pocket by Haas because the machine tool manufacturer wanted to see a driver take his company to victory lane. Busch was fired at the end of 2011 by Roger Penske for a series of on- and off-track incidents, and he spent two seasons driving for low-budget teams before Haas extended the olive branch.

Busch had been on a resurgence of sorts at SHR, which allowed him to compete in both the Indianapolis 500 and the Coca-Cola 600 on the same day last year. He finished sixth at Indianapolis last May and was named rookie of the race.

But his season began to unravel late last summer as his performance tailed off. Although he made the Chase for the Sprint Cup championship, he was eliminated after the first round.

It was the weekend of the first elimination race, at Dover, where Driscoll alleged Busch assaulted her in his motorhome.

She said she drove to the track out of concern for Busch, who sent her alarming text messages following a poor qualifying effort. She said the two argued in the bedroom section of the motorhome before he slammed her head against a wall three times.

Driscoll did not file charges until November, and the Delaware attorney general has not decided if Busch will be charged.

But Driscoll sought a no-contact order, and the couple spent four days over December and January in a Delaware court presenting their sides. At one point, he accused of her of being a trained assassin.

SHR said only that Smith, who filled in on short notice for Tony Stewart at Watkins Glen last August, would race Sunday. No plans were announced for next week's race at Atlanta, but since Haas pays for that car specifically for Busch, the team co-owner could conceivably park it if Busch does not win his appeal.