While full times were not released, indycar.com reported that Will Power topped the timesheets at the end of the day's running with a lap of 1:19.04s ahead of Scott Dixon (1:19.49s) and Dario Franchitti (1:19.60s).
Ryan Hunter-Reay came next with 1:19.77s ahead of EJ Viso (1:19.79s), with Pantano putting in a matching time on the 12-turn, 2.303-mile course.
Kanaan and engineer part company
Tony Kanaan has parted company with his race engineer Michael Cannon.
The split comes despite some impressive on-track performances of late, which have included a strong run at Milwaukee and third place at last week's race at New Hampshire Motor Speedway.
Cannon joined KV Racing Technology at the start of the season, having previously been with HVM engineering the car of Simona de Silvestro.
"It wasn't any one incident," said KVRT general manager Mark Johnson. "The deal came together late and there just wasn't any chemistry there so we made a change."