Five drivers to watch during the 100th Indy 500

(Reuters) - Five drivers to watch during the 100th running of the Indianapolis 500 on Sunday. HELIO CASTRONEVES Castroneves, 41, will try to join one of the most exclusive clubs in worldwide motorsports – four-time winners of the Indianapolis 500 - when he looks to add to triumphs recorded in 2001, 2002 and 2009. Should Castroneves prevail, he would become the fourth four-time champion, joining A.J. Foyt (1961, 1964, 1967, 1977), Al Unser (1970, 1971, 1978, 1987) and Rick Mears (1979, 1984, 1988, 1991). The Brazilian very nearly accomplished the feat in 2014 but was denied by American Ryan Hunter-Reay, who powered past him at the start of the final lap to win by less than a car length in one of the closest finishes in the race's history. - - SIMON PAGENAUD The Frenchman won his last three IndyCar races, including the most recent at the Indianapolis Motor Speedway road course earlier this month. He is the first IndyCar driver to win three straight since Scott Dixon in 2013. Pagenaud has not finished any worse than second through five races of the 2016 Verizon IndyCar Series season and could be on the verge of a monster campaign. His results are a huge change of pace from last year when he sometimes struggled amid sky-high expectations during his first campaign with Team Penske, one of IndyCar's most successful outfits with a record 16 Indy 500 victories. - - SCOTT DIXON The New Zealand driver and 2008 Indianapolis 500 winner will be eager to return to the starting grid at the Brickyard after an overheating issue plagued his car in last year's race, where he finished fourth. Dixon, who started from the pole in 2015, led a race-high 84 laps and still had the lead with 13 laps to run but a stray plastic bag that flew into his sidepod caused his engine to overheat and contributed to his fading finish. The reigning and four-time IndyCar champion has been one of the series' most consistent drivers, posting at least one victory in 12 of the previous 13 seasons. He secured win number 38 earlier this year in Phoenix. - - WILL POWER The Australian has said the sight of Team Penske teammate Juan Pablo Montoya crossing the Indianapolis 500 finish line 0.1 second ahead of him last year has stuck with him ever since. Power was in position for the win until Montoya made a bold pass on the outside with three laps to go and held on for his second career Indianapolis 500. Power, 35, has 23 IndyCar wins and a championship, but has never won the Indy 500 in eight attempts and has been vocal about it being the one race he craves more than any other. - - MARCO ANDRETTI The Andrettis may be the first family of American motorsport but when it comes to the Indianapolis 500, the clan has known mostly hard luck. Marco, grandson of Mario Andretti, will try to end what has become known as the Andretti Curse at the Brickyard when he takes the green flag for the 11th time. Mario raced in 29 Indy 500s, winning in 1969, while his son Michael holds the distinction of having led more laps at the Brickyard than any other driver never to win the race. Marco has finished second once and third three times. (Reporting by Frank Pingue in Toronto. Editing by Steve Keating.)