WEST ALLIS, Wis. — This was not what Helio Castroneves had in mind for the week after the biggest victory of his career.

Castroneves spent the past few days celebrating his third Indianapolis 500 win and talking about his next challenge — hanging onto the momentum from Indy and going after his first IndyCar Series championship.

The concrete wall in turn two at the Milwaukee Mile took the edge off the celebration and made things a little more difficult for the Penske Racing driver, who hit the barrier during qualifying for Sunday's A.J. Foyt 225 and will have to start last on the 20-car grid.

"We tried something different out there in qualifying from what we ran in practice," Castroneves said. "I just went for it and the car wiggled a little bit. I thought I saved it but, unfortunately, I ended up brushing the wall and couldn't qualify."

But Castroneves, still buoyed by the Indy win on top of the fact that he was acquitted in April on federal tax evasion charges that threatened his future, remained optimistic.

"The good news is that Ryan (Briscoe) is starting on the pole tomorrow, which shows that the Team Penske cars are strong," he said. "Tomorrow, we're going to look to have good pit stops and score some solid points."

If Castroneves has a good car, it may not be that tough for him to challenge Briscoe and the rest of the top qualifiers.

Last fall at Chicagoland Speedway, he started 28th after his qualifying effort was disallowed for driving below the white out-of-bounds line. Castroneves charged through the field to win, giving series champion Scott Dixon a scare as the Brazilian came within 17 points of the 2008 title.

At Kansas last month, it was more of the same.

Castroneves started from the back of a 21-car field after again being disqualified again for a white-line violation during qualifying. This time, he wound up second to Dixon.

But traffic on the flat Milwaukee track is always a hazard.

"This is a very difficult place because you're always in traffic," said Castroneves, who has qualified well here in the past, but has yet to win on the suburban Milwaukee track. "Things happen very fast and you have to have a good car and be a little lucky, too."

Teammate Briscoe, whose victory here a year ago put his open-wheel career into high gear, had no problems Saturday. His four-lap average of 168.394 mph gave the Australian driver his fifth career pole and first of 2009.

"We won from 11th last year so, hopefully, starting on the front row can get me away from the chaos that always happens the first couple of laps," Briscoe said. "I had a good race car last year so, hopefully, we can replicate that tomorrow."

Asked about the ill fortune that befell his teammate, Briscoe said, "He always seems to win the race when they put him in the back, so I'll be looking in my mirrors, for sure."

Graham Rahal, the 20-year-old second-year driver for Newman/Haas/Lanigan Racing, added a second-place start to two poles earlier in the season. His four-mile qualifying run of 168.117 was only 0.277 mph slower than Briscoe.

Tony Kanaan, still hurting from a hard crash in last Sunday's 500-mile race, was able to ignore the pain long enough to qualify third at 167.793.

"Everything hurts," Kanaan said. "But my mother told me before I came here just to suck it up and go. So I'm taking her advice."

Dixon qualified fourth at 167.089, followed by Mario Moraes at 166.791, Hideki Mutoh at 166.139, Danica Patrick at 165.168 and Dario Franchitti — leading Castroneves by five points in the season standings — at 164.706.