This weekend, the Dover International Speedway took sports bets for the first time, becoming the only track so far to allow gambling on a race.
Dover is based in Delaware, one of five US states where sports betting is legal, with the state regulating the practice just three weeks after the repeal of the Professional and Amateur Sports Protection Act in May.
Phelps is quoted as saying by the Associated Press: "I think for 2019, we'll have some rules that we'll put in place.
"For right now, there'll be betting here. We'll study and see how that goes, but I think we'll have some rules in place for sponsorship, for what betting looks like, and continue to see what happens in the landscape overall."
Notably, NASCAR does not currently stop its drivers or team members from betting on races.
However, Phelps said that some of the rules will be clarified next year, while also commenting on NASCAR's attractiveness to potential sponsors.
He said: "The way the rulebook looks today, I think the teams and the drivers understand what it looks like today, and I think we'll clarify for '19 with more specific language in it.
“From a sponsorship standpoint, I think sponsorship will definitely gravitate to NASCAR as most sponsors do because of the return on the investment they can get because of the visibility that it has,”
