TALLADEGA, Ala. -- Restrictor-plate racing presents a different set of variables for NASCAR officials, particularly when it comes to policing aggressive driving. And that was more than evident Friday at Talladega Superspeedway when Sprint Cup Series director John Darby warned drivers to tone down things after at least five cars were damaged in a crash just minutes after the start of the first practice session.

"Typically, the first seven laps off the truck, we don't tear a bunch of stuff up," Darby said. "We react to those kinds of things, and a bunch of wrecked race cars that early in the weekend doesn't make sense."

That incident concerned Darby enough to let everyone in the garage area know that NASCAR wasn't going to let things get out of hand.

"For a long time now at Daytona and Talladega, we've warned the drivers about aggressive driving," Darby said. "We will do that again [Sunday] for the race. More importantly, what doesn't make sense is to let aggressive driving go unnoticed or with no reaction in practice, where everybody's there to shake their cars down and get them ready for the race. To ignore that and have the potential to have a big wreck in practice, where all the teams have to go back and scramble for backup cars didn't make sense.

"So what we saw early on in practice [Friday] was that everybody was getting a little carried away and at the start of the second practice, we warned them to relax a little bit, do what they needed to do and stay off the aggressiveness."

The last two restrictor-plate races have ended in wild, last-lap crashes. The last time the series visited Talladega, Carl Edwards and Brad Keselowski made contact, with Edwards' car eventually winding up in the catchfence. At Daytona in July, Kyle Busch crashed hard after sweeping back across Tony Stewart's fender as the two battled for the win, with Kasey Kahne then rear-ending Busch.

With a drop in horsepower caused by a shrinking of the diameter of the holes in the restrictor plates, speeds have decreased. But the unintended consequences are that drivers must become more aggressive in their efforts to make passes, or pull away from the pack. And that's something Darby and his crew will be keeping a close eye on in Sunday's Amp Energy 500. (Continued)