JENNA FRYER, AP Auto Racing Writer

DAYTONA BEACH, Fla. (AP) - NASCAR driver Kurt Busch's final appeal hearing has started, beginning minutes after his younger brother Kyle was ruled out of the Daytona 500 with a leg injury.

If Kurt loses his appeal Saturday night, both Busch brothers would be out of the "Great American Race" for the first time since 2000.

Kurt lost his first appeal earlier Saturday when a three-judge panel upheld NASCAR's indefinite suspension, which was handed down Friday after a Delaware judge said the 2004 champion almost surely choked and beat a former girlfriend last fall at Dover International Speedway.

Kurt has one final chance in front of final appeals officer Bryan Moss, a former president of Gulfstream Aerospace.

Even if Moss overturns the suspension, Stewart-Haas Racing has moved forward with plans to use Regan Smith in Busch's No. 41 Chevrolet on Sunday. Chevrolet suspended its relationship with Busch shortly after the suspension.

Busch represented himself in the first appeals hearing at NASCAR headquarters, located across the street from Daytona International Speedway. Jim Cassidy, senior vice president of racing operations, represented NASCAR. The panelists were former NASCAR executive Paul Brooks, former driver Lyn St. James and Kevin Whitaker, operator of Greenville Pickens Speedway in South Carolina.

Following the hearing, Busch exited NASCAR's office building without comment. He climbed into a waiting SUV that sped off, squealing its tires.

He returned a few hours later for another plea.

Kyle, meanwhile, was hospitalized at nearby Halifax Health following a frightening crash late in the Xfinity Series season opener at Daytona. NASCAR officials ruled the Joe Gibbs Racing driver out a short time later, saying he was awake, alert and being evaluated.

Kyle was hurt when his car slammed head-on into an interior wall that did not have an energy-absorbing SAFER barrier. He was only able to climb halfway through his window and was seemingly pointing to his right leg when rescue personnel arrived.

Joe Gibbs Racing did not immediately announce a replacement for the No. 18 Toyota.

Kurt has been front and center since arriving at Daytona on Feb. 12.

A judge granted ex-girlfriend Patricia Driscoll's request for the no-contact order Monday, and three days later, Busch's legal team asked for an appeal on the grounds it had new evidence to present.

Kurt has maintained he did not assault Driscoll, but merely cupped her face as he requested her to leave his motorhome.

But the judge's opinion saw things differently, and NASCAR suspended Busch. It was the third suspension of the 36-year-old driver's career.

It's unclear what SHR will do beyond Daytona. Busch's car is funded out of pocket by team co-owner Gene Haas, who hand-picked the former champion to drive a car adorned with Haas' machine tools building company. He wanted Busch because he believed Busch could get the car to victory lane.

Haas has not commented since the Friday suspension, and he may not be willing to pay for the car if Busch is not behind the wheel.

"We haven't spoken about anything beyond that," SHR executive vice president Brett Frood said.

Smith drove co-owner Tony Stewart's No. 14 car last season at Watkins Glen after Stewart hit and killed a fellow driver who got out of his car in a short-track race. Smith, who has one Cup victory, also filled in two races in 2012 while Dale Earnhardt Jr. recovered from a concussion.

"He's a good fit, he's in the family and he'll get us through this week," SHR competition director Greg Zipadelli said. "It's a shame we are going through this, but it's what we are dealt. We'll make the best of it and see where it goes from here."