Moreno replaces injured Gregoire

Gregoire sustained a fractured vertebrae during a crash in practice on Thursday. Chastain said Moreno will be on track tomorrow for his refresher course and will attempt to qualify the car.

"I haven't known another driver than Stephan," Chastain said. "He's the only driver I've ever known, but we need somebody with experience to come in here and do the job real quick. From what I've been told, Roberto is the guy that can get the job done."

On Friday, the Chastain crew were rebuilding the car, which was moderately damaged when it spun and struck the wall tail-first about an hour into Thursday's practice session.

Gregoire appeared to be OK, but he went to Methodist Hospital about an hour after the crash, and a scan revealed an in-plate fracture of his third thoracic vertebrae.

Dr Mike Olinger, the Indy Racing League's director of medical services, said Gregoire was released from Methodist on Friday morning, but was not cleared to drive.

Moreno, the 48-year-old veteran who competed in 75 Formula One races in the 1980s and '90s, has become a designated substitute in recent years.

Most recently, he replaced injured Alex Figge in a Champ Car race last month at Houston. In 2006, he replaced injured Ed Carpenter in an IndyCar race at St Petersburg.

In other developments on Friday, Alex Barron was hired to drive the No. 98 CURB/Beck Motorsports Honda/Dallara.

The third day of qualifying, in which the 23rd through 33rd positions are expected to be filled, is scheduled for Saturday.