NASCAR Chief Executive Brian France told Fox Business News that while he "didn't agree" with what Keselowski said, the reigning champion had the right to say it.
Both Keselowski and fellow Penske Racing member Joey Logano were deemed by NASCAR to have failed the pre-race inspection in Saturday's NRA 500 at Texas Motor Speedway and were sent to the back of field.
Officials confiscated the rear-end housing and other parts on Keselowski's No. 2 Ford, as well as the same items on Logano's No. 22 car.
After his ninth-place finish, the angry champ said, "I have one good thing to say, and that's my team and the effort they put in today to fight back with the absolute [(expletive] that's been the last seven days in the garage area."
Asked by Fox if NASCAR would fine the driver, French replied, "No, we're not, because that's the beauty of NASCAR. We do allow the drivers to express themselves in that way, even if they say things that we would disagree with."