AJ Allmendinger, driver of the #22 Shell/Pennzoil Dodge, walks on the grid during qualifying for the NASCAR Sprint Cup Series Coke Zero 400 Powered by Coca-Cola at Daytona International Speedway on July 6, 2012 in Daytona Beach, Florida.
(July 5, 2012 – Source: Sean Gardner/Getty Images North America)

(PhatzRadio / USA Today) — A.J. Allmendinger has elected to exhaust his last challenge to a failed drug test that has the Penske Racing driver on temporary suspension, NASCAR confirmed Monday night.

In a written request, Allmendinger asked NASCAR for the “B” sample be tested in hopes of a negative result that would lead to immediate reinstatement. If the test is positive, Allmendinger would be suspended indefinitely.

He would need to complete a program created by NASCAR substance abuse program administrator Dr. David Black and a substance abuse professional that would be tailored to Allmendinger’s violation and that might include counseling, treatment or rehabilitation. Once Allmendinger completes the program, he would be considered for reinstatement of his license, though there’s no guarantee he’ll have a Sprint Cup— or any — ride waiting for him.

The sample will be tested at the Aegis Sciences Corporation in Nashville. The same laboratory also tested the “A” sample collected June 29 at Kentucky Speedway. The samples were collected together and then split.

NASCAR has indicated it could take up to five days for a “B” sample result. Allmendinger is allowed to be present or be represented by a qualified toxicologist outside of Aegis during the test for observation.

Allmendinger’s business manager told USA TODAY Sports earlier Monday that the positive test “was kind of shocking and surreal.”

“It took a little bit of Saturday night to believe it was happening,” Tara Ragan said in a telephone interview. “A.J. is very health-conscious, very focused and works out all the time. We were in a fair amount of shock for Saturday night, and we tried to regroup Sunday to figure out a game plan.”

Allmendinger is the second Sprint Cup driver to be suspended since the introduction of a new random testing policy for the 2009 season, but he is the first to be temporarily suspended.

Jeremy Mayfield was suspended indefinitely in May 2009 after a positive test at Richmond International Raceway. Court documents showed that his “B” sample was tested within 36 hours of being requested.

While the test results are pending, Sam Hornish Jr. will replace Allmendinger this weekend at New Hampshire Motor Speedway.