Eager to resolve his suspension for a failed drug test, AJ Allmendinger said Tuesday that he has formally asked NASCAR to test his second urine sample and insisted that he would never "knowingly" take a prohibited substance.

Allmendinger was informed hours before Saturday night's race at Daytona he had failed a random June 29 drug test. NASCAR does not disclose what substance was found, and Allmendinger and Penske Racing have not revealed details.

In his first statement since the suspension, Allmendinger confirmed Tuesday that he has requested his "B'' sample be tested and is following the steps listed in the 2012 rule book regarding the drug testing policy.

"I fully respect NASCAR's drug usage policy and the reasons they have it. I am hoping this can get resolved as quickly as possible so that I can get back to driving the No. 22 Penske Racing Dodge," he said. "I am sorry that this has caused such a distraction for my Penske Racing team, our sponsors and fans. Obviously I would never do anything to jeopardize my opportunity here at Penske Racing or to my fellow drivers. I am very conscious about my training and health and would never knowingly take a prohibited drug."

Team owner Roger Penske indicated he's supporting Allmendinger.

"I'm more concerned about the individual than I am the circumstance," Penske said on NASCAR's Sirius XM Radio channel. "Long-term, one way or the other, he's a fighter, he's a good race driver and I'm sure he'll be fine. This is a speed bump that neither one of us had contemplated, and we have to deal with it professionally."

The 30-year-old driver was tested at Kentucky Speedway and informed eight days later by NASCAR's medical review officer that he had failed the test. He had an opportunity to explain the results to the MRO before NASCAR was informed of the results.

Allmendinger and a senior Penske Racing official had a meeting with NASCAR after the sanctioning body was told of the result, and Allmendinger's suspension was announced roughly 90 minutes before the start of the race.

Penske Racing flew Sam Hornish Jr. in from North Carolina to drive Allmendinger's car, and Hornish has been tabbed to drive again this weekend at New Hampshire.

Allmendinger can only be re-instated for competition if the "B'' sample is negative. Otherwise, his only option is to complete a rehabilitation program designed by Aegis Sciences Corp. in Nashville, Tenn.

Allmendinger has the right under NASCAR's policy to watch the lab test his "B'' sample at Aegis, and he can also have an independent expert on hand. His statement gave no indication if he plans to attend the test.

Penske also told Sirius XM the organization is waiting for the process to be completed before making any decisions on its first-year driver.

"We're standing behind him until we understand the results," Penske said. "I can't really say today what that's going to be. I'm hoping the second test will find him clean and we can move on from this situation."

Allmendinger signed a one-year contract in December to replace Kurt Busch at Penske and the organization said as recently as two weeks ago that a contract extension was likely.

"I think we'll have to assess the situation, it's not something you just do overnight," Penske said. "We'll look at the details and understand it and we'll make our moves accordingly. The whole world's got an eyeball on him. He's a very good guy and I hate to see this."