NASCAR drivers pass drug tests; concerns turn to crews

"Looking at some of the over-the-wall guys, I have some concerns about these situations and the possibility of performance-enhancement," Sprint Cup rookie Brad Keselowski said.

All drivers from NASCAR's three national series (Sprint, Nationwide and Camping World Truck) passed the tests conducted by the lab tapped by the series, NASCAR spokesman Ramsey Poston said. Each race team, however, was responsible for testing its crewmembers — and some apparently hit snags.