DOVER, Del. -- Kevin Harvick and Kyle Busch may have to play nice on the track now that they're on probation.
Off the track?
Well, boys, have at it.
"It's kind of one lie after the other," Harvick said of Busch.
"He'll talk to you to your face like you're best friends, but then behind closed doors ... he has the utmost disrespectful thoughts," Busch said of Harvick.
The verbal smackdown that's been ignited between the NASCAR stars since their dustup last weekend at Darlington Raceway has turned Harvick-Busch into the feud of the week.
Harvick and Busch disagree about the incident that forced NASCAR to penalize them. And, they differ on NASCAR's interpretation of "Boys, have at it."
They did agree Friday at Dover International Speedway that they don't like each other.
"I've never gotten along with the guy," Busch said.
Harvick and Busch were fined $25,000 apiece and put on probation this week by NASCAR for their actions on pit road at Darlington. On Thursday, the drivers were summoned separately to the NASCAR hauler for a meeting with top officials.
NASCAR issued a brief ultimatum about what it means to compete while on probation -- and that Harvick's No. 29 Chevrolet and Busch's No. 18 Toyota shouldn't tangle too closely on the track.
The probation for all NASCAR-sanctioned events runs through June 15, a span that includes four Sprint Cup Series championship races and the non-points $1 million All-Star event.
The drivers got an early chance to prove they'll be on their best behavior in Friday night's Truck Series race at Dover. Harvick qualified second and Busch third.
Their already contentious relationship took another blow late in the race at Darlington after Busch made contact with Harvick.
Harvick said officials stressed he was penalized because of the postrace blow up on pit road. Last weekend at Darlington, Harvick climbed from his car and threw a punch into Busch's window just as Busch pulled away, using his car to bump Harvick's car out of the way.
The empty car turned and hit the inside wall. No one was hurt, but Harvick's crew members were running down pit road when the car hit the wall.
"I think they would back me whether I was right or wrong, they are going to back me up and I will do the same for them. That's the great part about our team," Harvick said.
"The No. 18 team is not backing him up, I mean when you don't have a backbone how do you back someone up?"
One-liners aside, safety issues were at the heart of the penalty. Pit road is no place for payback, especially once crew members and other personnel are out there.
NASCAR adopted a "Boys, have at it" policy at the start of last year that gave the drivers more leniency to police each other on the track.
For some, the penalties levied against the pair seemed to go against that easygoing stance.
"It's definitely to the point where it's a little bit confusing with how it all works," Harvick said. "I think when you look at the, 'Boys, have at it,' theme, it's obviously changing as we go through the process."
Surprise. Busch insisted he knew exactly what those words mean -- and so should everyone in the sport.
"When matters get taken into the drivers' hands or anything else onto pit road, where innocent bystanders can be injured or something, NASCAR is going to step in and they're going to intervene and they're going to set penalties the way that they feel need to be levied," he said.
NASCAR tradition is steeped in fights, feuds and rivalries.
They help create excitement for the sport and get fans talking. Maybe the Harvick-Busch feud could spark flagging ticket sales for Sunday's Sprint Cup race.
"I want to be a part of it because I want to sell the hats and the T-shirts," Greg Biffle said. "I don't want to be a part of it though, because I don't want to lose the points and be backward in the fence or have the radiator busted out of the car and finish 35th.
"It is fun for the sport though."