CHARLOTTE (AP) -- Suspended NASCAR driver AJ Allmendinger says he tested positive for a stimulant he did not identify.

A statement Wednesday from Allmendinger's business manager says the driver is collecting his medicines and supplements to determine if an over-the-counter product caused the positive test.

Allmendinger was randomly tested by NASCAR on June 29, and informed Saturday he had failed the drug test. His suspension was announced hours before Saturday night's race at Daytona.

He has requested his "B'' urine sample be tested, and it's not clear when that will occur.

Penske Racing has already said Sam Hornish Jr. will drive the No. 22 Dodge this weekend at New Hampshire.

Allmendinger said in a Tuesday statement he would never knowingly take something on the banned substance list.

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