John Wes Townley, 20, was cited for underage possession of alcohol on Thursday night in Las Vegas.
NASCAR allowed him to participate in Saturday’s Nationwide Series race at Vegas, though his future was unclear.
“I want to apologize to NASCAR, everyone at Richard Childress Racing and all of our sponsors,” the Zaxby’s-sponsored Townley said in a statement released during the race. "I made a big mistake and feel terrible about it.
“I have learned a valuable lesson and will do everything I can to make it up to those I have let down.”
Team owner Richard Childress said Townley was aware that he made “a serious error in judgment.”
“Drivers are human and make mistakes like everyone else,” Childress said. “However, we do not condone his behavior and will be handling it as an internal matter at RCR.”
NASCAR said in a statement it was "aware of the situation."
"We have met with the driver and addressed the matter with him directly," the statement said.
Stay tuned for more updates after the race.