The supercross season opens Saturday night at its usual first stop, Angel Stadium, but the outlook for the sport's championship is decidedly unusual this year.
After winning the supercross title for four consecutive years, Ryan Villopoto is racing overseas in the FIM Motocross World Championship this season.
So the Monster Energy AMA Supercross Series will crown a different champion for the first time since 2010, when Ryan Dungey won the title.
Supercross is the stadium version of off-road motorcycle racing, or motocross. The sport uses several hundred truckloads of dirt to transform Angel Stadium's infield into a treacherous, hilly course of curves and jumps.
Three of the series' first six races are held at Angel Stadium; the others will be on Jan. 17 and 31. The series' 17-race schedule ends May 2 in Las Vegas.
Dungey, 25, will be back with the Red Bull KTM team, and only one other former champion, Chad Reed, will join him in the field.
At 32, Reed is the series' oldest full-time rider, and he owns his own team. The Australian won the title in 2004 and 2008.
Another two-time champion, James Stewart, also was expected to compete. But last month, Stewart was suspended until Aug. 11 after the Suzuki rider failed a drug test following a race last April.
The test revealed amphetamines, a prohibited substance in the sport. But Stewart, 29, said it was due to prescription medicine and he planned to appeal.
Villopoto's replacement at the Monster Energy Kawasaki team is Davi Millsaps of Murrieta, who won the season-opening race in Anaheim in 2013 but missed the 2014 season with a knee injury.
"I have the equipment to win," Millsaps said. "The goal is to be up front all season long and ultimately take home a championship."
Among the other top riders gunning for their first title are Ken Roczen of the RCH Racing team and Justin Barcia, who moved to Joe Gibbs Racing's team this season.
Saturday night's slate of racing, which starts at 6:30 p.m., includes qualifying heats and ends with the 20-lap main event scheduled for 9:25 p.m.