Rain washed out all track activity Friday at Charlotte Motor Speedway, which will now try to cram it's All-Star weekend into one day.

The steady showers forced NASCAR to call off the scheduled Sprint Showdown, a race that will send five drivers not already qualified for the All-Star race, into the main event. The Truck Series race also was postponed.

Both events were rescheduled for early Saturday, with the $1 million All-Star Race still scheduled to go off in the evening. NASCAR set the showdown field by points.

The lack of track time Friday could be problematic for many race teams. NASCAR only announced the format for the All-Star race on May 6, and the rules were not given to teams until earlier this week.

The Sprint Showdown is divided into three segments, and the winner of each segment will advance into the All-Star race. An additional two drivers will get into the All-Star race on a fan vote.

The All-Star race already has 15 drivers in the field. All drivers who won a race last year are eligible, as well as past All-Star race winners Tony Stewart, Jamie McMurray, Ryan Newman and Kasey Kahne.

The All-Star race will be 113 laps divided into three segments. The first 50-lap segment will require drivers to make a minimum two-tire pit stop under green. The drivers then will be required to do a minimum two-tire pit stop during the first break and start the second segment the way they come off pit road.

The second segment will also be 50 laps and also require a minimum two-tire pit stop under green before the 35th lap of the segment. There will then be a draw to determine whether the first nine, 10 or 11 cars will have to do a four-tire pit stop during the break while the remaining cars will not be allowed to pit.

The cars that pit will line up behind the drivers who weren't allowed to pit.

The final 13-lap segment will count only green-flag laps as drivers with fresh tires try to gain the lead from the drivers on old tires.

"It's going to be very interesting to see how it all plays out," said Denny Hamlin. "As a driver, there's going to be a lot of strategy played with crew chiefs and drivers."

NASCAR this week updated the rules package to reduce downforce and side force for the All-Star race. The idea is to reduce the speed in the corners in an effort to promote more passing. Drivers like less downforce because it puts the control of the car in their hands and allows the talent to rise.