Brooklyn, MI (Sports Network) - Dale Earnhardt Jr.'s shot at a season sweep at Michigan International Speedway will be a tougher task than expected after he crashed during Saturday's final practice session for the Pure Michigan 400.

Earnhardt Jr., who ended his four-year, 143-race winless streak two months ago at Michigan, will have to start from the rear of the field in Sunday's 400- mile race in a backup car after badly damaging the back end of his primary vehicle in a wreck during the closing minutes of the session.

The Hendrick Motorsports driver lost control and spun around before backing it into the turn two wall. His team immediately pulled out the backup car from the hauler. He did not get any practice time in that car.

Earnhardt Jr.'s primary car was the same one that he used to win here in June.

His teammate, Jimmie Johnson, will also start from the rear of the field after his No. 48 team made an engine change prior to practice.

"The guys (No. 48 team) saw something in warm up this morning, and we were trying to sort through it before practice started," Johnson said. "They took a deeper look at things right before practice started and decided to change it. We probably could have run some of this practice, but I think we had to change the engine regardless, but we didn't want to oil the track or create an issue and crash our car."

Greg Biffle led the way in the last practice with a lap at 198.879 mph, while Johnson had the second quickest lap at 198.222 mph. Earnhardt Jr. was 12th on the speed charts (196.576 mph).

On Friday, Johnson qualified third for this race, and Earnhardt Jr. placed 22nd. Fifty-three-year-old Mark Martin will start on the pole.

With 22 laps remaining, Busch and Sauter pitted from first and second to begin a round of green-flag stops. Sauter came out ahead of Busch, who spun his tires while exiting his stall.

The Sports Network