Rookie driver Robert Doornbos is the fastest during early practice for the Indianapolis 500.

Thursday's practice began about 20 minutes after its scheduled start because of a still-wet track, but by midday Doornbos was at more than 223 mph, just ahead of Penske teammates Ryan Briscoe and two-time Indy winner Helio Castroneves. Defending champion Scott Dixon and his Ganassi Racing teammate Dario Franchitti were right behind at more than 222.

Stanton Barrett became the sixth rookie to pass the mandatory driving test, and veteran Townsend Bell landed a ride with KV Racing Technology.

Bell, who was 10th in his second race at Indy last year, does not plan to practice until next week because of the late deal with KV Racing. His teammates are Paul Tracy and Mario Moraes.