You may have read the news that Coloradan Tejay van Garderen will not race in this year's USA Pro Cycling Challenge due to his participation in the Tour of Spain. As the two-time defending champion and perhaps the world's best high-altitude racer, van Garderen would have been the favorite to win this year. 

His absence has created an unpredictable and exciting scenario: Nobody knows who will arrive in Denver in first place. A few days ago we broke down the segments of this year's race that will likely decide the victor. Whoever wins must excel at high-altitude climbs and individual time trials. 

Below, we've highlighted 10 riders who could win. 

Rohan Dennis (Team BMC)
Riding in van Garderen's place on Team BMC is Australia's Rohan Dennis. Dennis is one of the world's premier time trialists, and earlier this year he won the Stage 1 time trial at the Tour de France. If you're picking a winner for the Stage 5 time trial in Breckenridge, Dennis is your man. Dennis is a strong climber as well, but the question is whether he can follow the best climbers at high altitude. If he can survive the climbs up Independence Pass and Arapahoe Basin, Dennis is the favorite to win it all. 

Damiano Caruso (Team BMC)
If Dennis falters in the climbs, BMC has another man who can win it all: Damiano Caruso of Italy. Caruso finished 8th at this year's Tour of Italy. He's a world-class climber and a strong time trialist as well. Caruso and Dennis give BMC a double punch that the team previously had in 2013, when van Garderen and Matthias Frank finished 1st and 2nd.

Janier Acevedo (Cannondale-Garmin)
Two years ago Janier Acevedo nearly stole the show at the USA Pro Challenge, winning one stage and finishing 3rd overall while riding with the Jamis-Hagens Berman squad. That result earned him a job with Cannondale-Garmin. This year he returns as co-leader of the squad. The Colombian excels when the roadgoes uphill, so Acevedo should be a favorite to win into Arapahoe Basin on Stage 2. His time trialing is a weakness, however. 

Davide Formolo (Cannondale-Garmin)
Cannondale-Garmin's young Italian rider Davide Formolo has already won a stage of the Tour of Italy this year. He's only 22, and is definitely a rider for the future. He'll co-lead Cannondale-Garmin alongside Acevedo and could be a major factor on the climbs. 

Roman Kreuziger (Tinkoff- Saxo)
On paper, Czech rider Roman Kreuziger is the most experienced stage racer at this year's event. He's finished top-10 at the Tour de France on three occasions, and has also won major stage races in Switzerland. But, as we've seen in previous years, European racers often struggle with Colorado's thin air. If Kreuziger can beat the altitude, he will challenge for the overall.

Matthew Busche (Trek Factory Racing)
Earlier this year Matthew Busche outfoxed three Cannondale-Garmin riders to win the U.S. National road race. He's been pretty quiet since then, and could be looking to the USA Pro Cycling Challenge for his next big result.

Julian Arredondo (Trek Factory Racing)
Trek Factory Racing's Julian Arredondo is probably the best climber in the bunch this year. He won the King of the Mountains award at the 2014 Tour of Italy, and has won uphill races in Malaysia, Italy and Argentina. Like Acevedo, Arredondo hails from Colombia.

Rob Britton (Team Smartstop)
Although he rides for the smaller Team Smartstop, Canada's Rob Britton is a strong climber and a talented time trialist. In May, he won the overall at New Mexico's Tour of the Gila, which is also held at high altitude. Don't count out Britton and the riders from the smaller Continental squads.

Daniel Jaramillo (Jamis-Hagens Berman)
Like Britton, Daniel Jaramillo rides for a Continental-level team, and could factor into the overall if the larger squads do not take him seriously. Hailing from Colombia, Jaramillo is a talented climber.

Toms Skujins (Hincapie Racing Team)
A rising star on the Hincapie development squad, Skujins won a stage of the Tour of California earlier this year after a long breakaway. He also finished 2nd overall in Canada's Tour de Beauce. Keep an eye on him - Skujins is a rider for the future.

About the author: 
Fred Dreier is a journalist living in Denver, Colorado. 
He has written about professional bicycle racing since 2004, and his work has appeared in a wide variety of magazines and newspapers, such as The New York Times, The Wall Street Journal and USA Today. Dreier has covered the USA Pro Cycling Challenge since its debut in 2011. He regularly rides his bicycle on many of the roads used by the race.