Bradley Wiggins' attempt to pull off the rare Giro d'Italia-Tour de France double begins Saturday when the Italian classic starts in Naples with doping still clouding the sport.
The Briton followed up his Tour de France victory last year by taking gold in the time trial at the London Olympics, and Wiggins is the top favorite for the three-week Giro.
Vincenzo Nibali of Italy is regarded as his top challenger, while defending champion Ryder Hesjedal could also contend again.
However, the pre-race attention in the sport remains on a Spanish court's decision Tuesday to destroy the blood bags seized in the seven-year-old Operation Puerto case.
Spanish doctor Eufemiano Fuentes was found guilty of endangering public health and given a one-year suspended jail sentence in the case. But the World Anti-Doping Agency is considering a possible appeal of the ruling by Judge Julia Santamaria, who ordered the destruction of more than 200 bags of blood and other evidence gathered in police raids on Fuentes in 2006.
Michele Scarponi, who was awarded the 2011 title after Alberto Contador was stripped of the honor in another doping case, was banned in the Puerto case, and it will be interesting to see how he reacts to the verdicts.
Two-time Giro winner Ivan Basso, who also served a ban from the Puerto case, withdrew Thursday citing a cyst in the seat area.
As for the racing, it could come down to a contest between Wiggins' time trialing ability and Nibali's climbing prowess — or vice versa: how each rider performs in their rival's strongest areas.
Nibali's biggest victory thus far remains the 2010 Spanish Vuelta title. In last year's Tour he finished third behind the Sky duo of Wiggins and Chris Froome.
While Wiggins had declared all along that the Giro was his top priority this year, earlier this week he indicated that he might challenge Froome instead of help him in the Tour.
Nobody has pulled off the Giro-Tour double in the same year since Marco Pantani accomplished the feat 15 years ago.
"The main thing is to win the Giro. That's the first hurdle," Wiggins said before departing from England. "That's the one really at this stage and I don't look beyond that. It's like the first gold medal in the Olympics."
Nibali, meanwhile, has his entire focus on the Giro, and will have the home fans' support.
"The Giro has been our declared goal since the start of the season," Astana team manager Alexandre Vinokourov said. "We're all working exclusively to help Nibali win."
Wiggins won the opening-day time trial at the 2010 Giro in Amsterdam and wore the leader's pink jersey for one day before finishing 40th overall. However, his climbing ability has improved drastically since then.
"I may lose 20 seconds (to Nibali) on a bad day but I'm confident I can stay with him, no matter what he throws at me," Wiggins said. "But that's all I have to do because I'm confident that in the time trials I can take time on him."
Nibali finished third in the 2010 and 2011 Giro and was moved up to second in 2011 after Contador's suspension. Having moved from Liquigas to Astana, Nibali no longer has to split leadership with Basso.
This will be the fifth Giro for both Wiggins and Nibali. They already went head-to-head in the four-day Giro del Trentino last month, which Nibali won while Wiggins struggled with mechanical problems in the final stage.
Hesjedal, meanwhile, has had a quieter buildup. But his combined skills of climbing and time trialing, with solid support from a strong and experienced Garmin squad, make him a threat.
While Froome, Contador and the injured Joaquim Rodriguez are each absent, other contenders include 2011 Tour winner Cadel Evans, Scarponi and Robert Gesink.
The race begins with a 130-kilometer (81-mile) sprinting stage in downtown Naples, which should draw large crowds to watch the likes of Mark Cavendish, Matthew Goss, John Degenkolb and Daniele Bennati fight for the first pink jersey.
It's the first time in 10 years that the race has opened with a sprinting stage, and Cavendish — who has won a combined 36 stages at the Giro, Tour and Vuelta — is undoubtedly the man to beat.
But Cavendish won't have Alessandro Petacchi as a lead-out man now that the UCI has blocked the Italian's attempt to join the Omega Pharma-Quick Step team after announcing his retirement from the Lampre squad.
Wiggins could feature high on the leaderboard after Sunday's second stage, a 17.4-kilometer (10.8-mile) team time trial on the island of Ischia, a discipline his Sky squad excels in.
In all, there are three time trials for a total of 92.8 kilometers (58 miles).
Remaining in the Naples region, Stage 3 travels along the picturesque Amalfi coast. The course then heads down into the southern region of Calabria before turning north again into Basilicata. After a few stages in central Italy, the serious climbing begins in the north.
Including an uphill time trial for Stage 18, there are eight major climbing stages, with the final week including legendary peaks like the Galibier (one of two stages passing through France), the Gavia and Stelvio (in the same stage) and the Giao pass and Tre Cime di Lavaredo peak in the penultimate leg.
The race finishes in Brescia on May 26. (AP)