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.