Updated

Kansas City, KS (SportsNetwork.com) - Hendrick Motorsports drivers Jimmie Johnson and Dale Earnhardt Jr. had their championship hopes jeopardized after both of them crashed in separate incidents during Sunday's Hollywood Casino 400 at Kansas Speedway.

The 400-mile race at Kansas is the first race in the second round of the Chase for the Sprint Cup championship. Johnson and Earnhardt are among the 12 drivers who advanced into the Contender Round.

Johnson, who is attempting to win his record-tying seventh championship in NASCAR's premier series, spun out and crashed into the inside retaining wall after he was hit from behind by Greg Biffle, who was eliminated from title contention last weekend at Dover -- the last race in the opening Challenger Round.

The incident occurred on lap 85, just after a restart. Biffle got loose and slid into the back of Johnson.

"I'm fine, but obviously this is a big hit in championship points," Johnson said. "That will put a premium on next week (Charlotte) and the week after (Talladega)."

At the same time Johnson and Biffle made contact, Justin Allgaier and Josh Wise got together and crashed.

Johnson spent 68 laps behind the wall for repairs before returning.

While leading on lap 121, Earnhardt blew his right-front tire and made contact with the wall. He suffered significant damage to the right side of his No. 88 Chevrolet.

"The whole surface of the tire just unwound like a string," Earnhardt said. "It just came off the car, and it popped off the corner. I felt it coming apart through the corner."

Earnhardt had led a total of 45 laps. He also returned after repairs, 58 laps down.

After the Oct. 19 race at Talladega, the Chase field will be trimmed to eight drivers for the next round, the Eliminator Round.

The series will compete at Charlotte next Saturday night. Johnson won there for a record seventh time in May.

"This means we've got to be on our game at Charlotte and Talladega," Johnson said. "There's still a lot of racing left, and other stuff can happen. So we'll see how the other Chase drivers will do. We'll do our best to get back on track and get some wins."