Earnhardt and Mears on probation.

Dale Earnhardt Jr. and Casey Mears were penalized Tuesday for intentionally bumping cars after the race at Phoenix International Raceway.

NASCAR put both drivers on probation for the next six races, but neither was fined or lost any points. It was an about-face from Saturday night, when officials said they would not punish the drivers for their post-race skirmish.

"We had a weekly competition meeting, we had a good discussion about it, and we decided to put the drivers on probation so the situation did not escalate," said NASCAR spokesman Ramsey Poston.

Contact between the two caused Earnhardt to crash with 11 laps to go in Saturday night's race, spoiling what had been a good run. He led 63 laps and was likely headed to a top-10 finish, but the accident dropped him to 31st.

After the race, Earnhardt intentionally spun Mears on the cool-down lap. Mears retaliated by passing several cars on pit road to find Earnhardt, then bumping into the back of his car.

The two were teammates last year at Hendrick Motorsports, but Mears now drives for Richard Childress Racing. Both are having disappointing seasons so far. Earnhardt is 19th in the standings and Mears is 22nd.

Their probation begins this weekend at Talladega Superspeedway and runs through the May 31 race in Dover, Del.