On Sunday he will be back in the Portuguese national colours he wore in Florence when he outwitted and outsprinted Joaquim Rodriguez to win the the world title, his days in the iconic rainbow jersey over unless he can take a second consecutive victory. That has not been done since Paolo Bettini in 2006 and 2007 but Costa is nonetheless a contender.
Costa's last race in the rainbow jersey was the Coppa Agostoni in Italy last week. It is a minor race and not part of the WorldTour but was important for his Lampre-Merida team, which is based nearby in the outskirts of Milan. He also had a minor role in a move filmed around the race staring Taiwanese actor Eddie Peng.
"It's a little bit sad that my year as world champion is almost over, I'm going to miss it if I don't win it again," he told Cyclingnews, knowing he may have to soon wear the Lampre-Merida pink and blue instead of his all white kit decorated with the rainbow bands.
He seemed to savour every moment as world champion, always wearing a smile to match his special jersey and always happy to talk about his racing and pose for photographs with the many Portuguese cycling fans who live and work around the world, and always cheered for him at races.
"I've tried to enjoy my year as world champion, whatever has happened, in the good moments and in the bad moments," he explained.
"I've got some new objectives in life now my year as world champion is over, but the most important thing is to be able to say that I got to wear the rainbow jersey. That's special."
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Happy with his season as world champion
Costa managed to avoid the curse of the rainbow jersey and enjoyed his year as the world champion, with his victory earning him huge attention at home in Portugal, where he beat football player Christian Ronaldo to become Sports Personality of the Year. He failed in his attempt to prove his Tour de France credentials after being diagnosed with bronchial pneumonia, but won a third Tour de Suisse in June, was third overall at the Tour de Romandie and was second in the recent Grand Prix Cycliste de Montreal, indicating he has the form to possibly take a second consecutive world title.
"I'm pretty happy with my season. I was unlucky to be ill at the Tour de France and I had to pull out, but I think I did pretty well in the other races I targeted. I won the Tour de Suisse for a third time and then was pretty consistent throughout the season. I think I honoured the rainbow jersey."
Despite suffering at the Tour de France, he will again try to target the yellow jersey in 2015. His best overall placing was 18th in 2012 but his three stage victories in the mountains and his success at the Tour de Suisse, leaves him convinced of his ability.
"I think I'll target the tour de France again in 2015. I've still got some questions to answer and see how good I can be in a three-week race," he said.
"I'll sit down with team and discuss things but in theory the Tour will be my goal again for the summer."
The next objective is the world championships in Sunday. Portugal does not have a full nine-rider team but Costa can count on the support of Lampre-Merida teammate Nelson Oliviera, André Cardoso, José Mendes, Sérgio Paulinho and Tiago Machado.
His post-Tour bronchial pneumonia meant he did not race for more than a month in the summer but opted to stick to his scheduled race programme and race in Canada rather than try to ride into form via the Vuelta a España. He seems to have done the training and his second place behind Simon Gerrans in the Montréal sprint, after going on the attack several times on the final lap, bodes well for Sunday.
Just as he did in Florence, Costa is hoping to fly below the radar of the major nations and hopes to be in the finale of the race to use his often decisive tactical skills and fast finish.
"I think I'm going well but I don't know what I can do," he said playing his card close to his chest.
"I think there are lot of good riders who will be up there. I'll be watching people like Fabian Cancellara, Vincenzo Nibali, Peter Sagan and Alejandro Valverde. Let's see what happens in the race."