Suspended NASCAR driver A.J. Allmendinger has agreed to participate in a recovery program after violating the series' substance abuse policy.

In a statement issued Wednesday by Allmendinger's business manager, Tara Ragan, Allmendinger says he will participate in NASCAR's "Road to Recovery" program. The program includes an evaluation by a substance abuse professional, counseling or rehabilitation.

NASCAR has suspended Allmendinger indefinitely after a test of his backup urine sample conducted Tuesday confirmed an initial positive test in late June. The series has not said what substance Allmendinger tested positive for. Allmendinger has said he tested positive for a stimulant and did not knowingly ingest a banned substance.

Allmendinger, who is with Penske Racing, says he has hired an independent laboratory in an attempt to find what triggered the positive test.