Robby Gordon has been placed on immediate probation for an unspecified period after a post-qualifying incident in the Sprint Cup Series garage Friday evening at Las Vegas Motor Speedway.
NASCAR wouldn't specifically say what Gordon did, but described its probation move as an "emergency action."
"His actions were brought to our attention early last evening," NASCAR spokesman Kerry Tharp said. "We met this morning and reviewed the situation, and have reacted accordingly. We will continue to look at this situation involving Robby Gordon."
NASCAR vice president of competition Robin Pemberton described the incident as a "heated discussion" but wouldn't confirm it was a physical confrontation because he didn't personally witness it, nor did any NASCAR officials.
"You'll have to find somebody that actually saw it," Pemberton said.
The incident was brought to NASCAR's attention by Conway, Pemberton said. Conway will not be penalized.
Gordon and Conway didn't immediately respond to requests for comment. The two have had recent battles in the legal system over money.
A user named "Allen" on TheHotLap.com posted last night that he "got to see Robby Gordon and Kevin Conway get in a fight in the garage today."
Asked what happened by fellow users, Allen wrote: "Not sure but Robby had him by the shirt shaking him then put him to the ground and hit him once then slapped. Was short but I'm not sure if it means anything yet."