Indianapolis ? Alex Barron had every reason to be optimistic about returning to the Indianapolis 500 after being its co-rookie of the year in 2002.

But it didn’t work out that way. Inexplicably, he had no car to drive when he arrived two weeks ago at Indianapolis Motor Speedway, and could do nothing but wait and hope.

His patience was rewarded. A relieved Barron was back on the track Thursday, turning laps as a replacement for injured two-time champion Arie Luyendyk.

“It was a long trip being here two weeks and not having anything,” he said. “Unfortunately, it’s part of the career and you have to dig down.”

For Barron, the month has been filled with angst.

As practice for the race began, Barron figured it was only a matter of time before he received an offer to drive. Nine days later, the call finally came.

Thursday, he managed 32 laps and produced a top speed of 226.230 mph. He was the fastest of seven drivers on the track who have yet to qualify for the race.

Barron never expected finding a job would be so difficult.

After finishing fifth in the IRL points, winning at Nashville, Tenn., and coming in fourth at Indianapolis last year, Barron seemed to be a driver on the rise.

Driver Alex Barron prepares for practice at Indianapolis Motor Speedway. Barron is replacing the injured Arie Luyendyk.

Apparently few noticed.

His only IRL start this year came in Japan, when he replaced Gil de Ferran for Team Penske. Barron started 12th and finished 17th.

With de Ferran back, Barron again was out of work — until Luyendyk decided not to drive in this year’s race. Luyendyk has had back pain and headaches since a hard crash in practice last week, and was in Barron’s thoughts as practice ended.

“I’ve not talked with Arie a lot, but I wanted to make sure he’s OK,” Barron said. “I know it’s really hard for him, but you have to appreciate everything he’s accomplished around here.”

Drivers like Barron are the IRL’s hope for a full field. The race is in danger of being run with fewer than 33 cars for the first time since 1947.

Only eight of the traditional 11 three-wide rows were filled in last Sunday’s qualifying, and the last day of qualifying is this Sunday. Last Saturday’s time trials were rained out and there’s a chance of rain again this Sunday.

There are 54 cars at the track, and 56 drivers have passed physicals. But time is running out for combinations of drivers, teams and sponsors to emerge.

Rookie Tora Takagi of Japan had the fastest lap Thursday, going 229.157. It was the second straight day and third time this month that Takagi has been the fastest.

All eyes were on the non-qualifiers, though. Joining Barron on the track were Jimmy Vasser, Billy Boat, Jimmy Kite, Shigeaki Hattori of Japan, and Brazilians Airton Dare and Vitor Meira.

If all of them qualify this weekend, two spots would still be open. The question is whether they will be filled.

Team owner Chip Ganassi has two empty cars and Roger Penske has six, but neither appears eager to add drivers.