There was one driver change heading into the event. 1999 U.S. F2000 National Champion and two-time Indy Lights series winner Dan Wheldon joined Panther Racing to partner Hornish for the final two races of the season. He travelled to Chicagoland Speedway in June to further acquaint himself with IRL. Wheldon said he was looking forward to be associated and working with Panther Racing, and spoke of his feeling it was a good opportunity to learn with the team's personnel. 1999 Indy Racing League champion Greg Ray was hired to drive the No. 20 Sam Schmidt Motorsports car for the rest of the season after asking his former manager A. J. Foyt to be released from his contract. Ray filled the place of the team's regular driver Richie Hearn who broke his foot at the Belterra Casino Indy 300 in August 2002. Four practice sessions were held before the Sunday race; two on Friday and Saturday. The first and second sessions lasted 90 minutes, the third 60 minutes and the fourth 30 minutes. The racers were split into two groups, which were each allowed to run laps for half a session. Conditions were warm and sunny for the Friday practice sessions. The first yellow caution flag came out when Hideki Noda's engine failed leaving the fourth turn and stopped on the backstretch; he did not participate in the second session because his team was changing his engine. The second was shown after Giaffone hit the outside retaining barrier between turns three and four, and Hornish was involved, bending his left-front suspension, his front wing and his chassis tub was punctured. Both drivers were uninjured. Buddy Rice was the session's fastest driver with a time of 24.4578 seconds, ahead of Eddie Cheever Jr. in second, and Billy Boat third. Vítor Meira and Sarah Fisher rounded out the top five. Hornish's left-front section of his car was repaired for the second session, where he recorded the fastest lap of 24.4910 seconds; Cheever was second and Rice third. Al Unser Jr. and Giaffone followed in the top five. Two caution flags came out for track inspections. The third practice session was held under sunny and warm weather conditions and had Unser set the fastest lap at 24.5953 seconds. He was followed by Rice in second, and Meira came third. Boat was fourth-quickest, and rounding out the top five was Robbie Buhl. An hour after the third practice session ended, the 25 drivers determined the starting grid through qualifying.