Indy 500 has favorites, but also several potential spoilers ready to strike

Reporting from Indianapolis

Drivers racing for Roger Penske and Chip Ganassi again are favorites to win the Indianapolis 500 on the 100th anniversary of the race Sunday.

Penske is an Indy legend, with a record 15 of his drivers winning the Memorial Day weekend race. This year, his team includes three-time winner Helio Castroneves, Ryan Briscoe and Australian Will Power, who leads the Izod IndyCar Series point standings.

Ganassi’s drivers are Dario Franchitti, the two-time and defending Indy 500 winner, and Scott Dixon, who won the race in 2008.

But who are the dark horses in this year’s 33-car field? Here’s a look at some of the drivers who have an outside chance of reaching Victory Lane:

Dan Wheldon — The 32-year-old Brit won the Indy 500 and the series championship in 2005 for the former Andretti Green Racing team, but he was winless in 2009-10 and found himself without a full-time ride this season.

But a team led by veteran driver Bryan Herta signed Wheldon to drive in this year’s Indy 500, and Wheldon responded by qualifying sixth with an average speed of 226.490 mph at the Indianapolis Motor Speedway, so he will start in the second row.

Wheldon also has finished second the last two consecutive years, when he drove for Panther Racing, and he has finished fourth or better in four of his eight previous Indy 500s.

Alex Tagliani — When the Canadian won the Indy 500 pole position a week ago, few observers considered it a fluke, even though Tagliani has only one victory in a decade of competing in the top levels of U.S. open-wheel racing.

This year the loquacious Tagliani, 38, is driving for Sam Schmidt Motorsports, and he has been fast all month at Indianapolis.

“We have a one-car operation and everything is focused on that one car,” he said. “We were not out to lunch. A lot of people didn’t believe that . . . with the level of competition, we would even be a factor.”

As he leads the field to the green flag, Tagliani said his strategy will be simple: “Stay in the front all day. I don’t want to go in the back, nobody wants to be in the back. It becomes more unpredictable. You’re banging wheels with people, stuff happens.

“Getting it done, that’s a different thing, you need luck. The stars need to be aligned, everything needs to be perfect. It has to be your day.”

Tony Kanaan — The veteran Brazilian driver also lost his full-time ride this year with Andretti Autosport because of a lack of sponsorship, but the KV Racing Technology/Lotus team hired the 36-year-old to drive in this year’s Indy 500.

Kanaan, who qualified 22nd, has the unwelcome distinction of being considered one of the best drivers never to have won the race. The 2004 series champion, he has led a combined 214 laps at the Brickyard in his previous nine starts.

Kanaan was running second to Franchitti near the end of last year’s race when he was forced to pit for fuel. Franchitti went on to win and Kanaan finished 11th.

Danica Patrick — If there’s one place where the popular IndyCar driver might win her second series race, perhaps before she jumps to NASCAR stock car racing, it’s the Indianapolis Motor Speedway.

Patrick, of course, nearly won here in her rookie year in 2005, and has performed well at the Brickyard nearly every year since. She starts 25th on Sunday.

She finished third in 2009, sixth last year and has finished out of the top 10 only once in her six previous Indy 500s (22nd in 2008). Patrick also has completed every lap in five of her six races.

The question Sunday will be whether her Andretti Autosport team can find enough speed for her, as the entire team struggled in qualifying.

Oriol Servia — This Spanish driver for Newman-Haas Racing also has won only once in his decade-long career, but he put himself in the front row for Sunday’s race by qualifying third at 227.168 mph.

Servia, 36, drove well in the first four races of this season and is third in the title standings, but all those races were on road or street courses, not oval tracks such as Indy.

james.peltz@latimes.com