CHARLOTTE, N.C. -- A prominent authority on drug testing says the indefinite suspension of Sprint Cup driver Jeremy Mayfield further enhances his belief that the sport needs to provide a public list of banned substances to protect itself legally.
Mayfield on Saturday became the first Cup driver suspended for violating the substance abuse policy.
Sources close to the situation said Mayfield claims he took Claritin D, an over-the-counter allergy drug that contains pseudoephedrine, a substance banned by most sports.
Mayfield said in a prepared statement that the positive test was the result of combining a prescribed and over-the-counter drug, a possibility the doctor who runs NASCAR's drug testing policy denied was plausible.
"A combination of an over-the-counter drug taken with a prescription drug could not cause the positive that we took action on," Dr. David Black of the Tennessee-based Aegis Labs said.
But what concerns Dr. Charles Yesalis, a Penn State professor who has testified before Congress on performance-enhancing drugs and spent 25 years researching drug testing, is that drivers are not provided a list of banned substances.
The NFL, NBA, MLB, PGA Tour and NCAA each make available public lists in their drug testing policies.
"That alone to me is ludicrous," Yesalis said Monday. "That just kind of violates your sense of fair play. It never would fly in MLB or the NFL because they have a union.
"The drivers don't have a union, but if somebody did that to me I'd go get myself a nasty lawyer. What if somebody in management or ownership doesn't like you? They can use that as a weapon against you."
Black said the lack of a list makes the program stronger because it gives the governing body more flexibility.
"We've had a policy since 1988 without a rift where we always allowed ourselves on any given case to determine whether or not a drug we identify will be prohibited by the policy in the program," he said. "We've actually had positives on drivers in our reasonable suspicion program."
NASCAR went this season from testing for reasonable suspicion to mandatory preseason tests and random weekly tests. Four to eight drivers and eight to 15 crew members randomly are tested each weekend.
The program has resulted in the suspension of numerous crew members, including one with Mayfield's team earlier in the season. But until Saturday no Cup driver had been suspended.
"[Mayfield] can say whatever he wishes to say," Black said. "I think we're on very, very good ground. I'm very confident in the interpretation of the test and the action we took."
Yesalis doesn't disagree that the findings of the test are legitimate. He, too, never has come across a positive test caused by the use of Claritin D, although "if somebody doubled or tripled the dose I wouldn't want to be next to them at 190 miles per hour going into the first turn at Darlington."
But for legal reasons he believes NASCAR needs to be more up front with what it is looking for.
Because his is not considered an appealable offense, legal action could be Mayfield's only recourse if he chooses to fight the suspension. Sources close to the situation said that hasn't been determined yet.
"They should have a formal list that the drivers and pit crews and everybody knows here's the rules," Yesalis said. "That list should be specific."
David Newton covers NASCAR for ESPN.com. He can be reached at email@example.com.