Britain's David Millar insists he is close to rediscovering his best form after finishing the Tour de France in 59th place on Sunday.
Millar will target a high finish in the Vuelta's overall standings
The Scot was taking part in his first competitive event after completing a two-year ban for doping offences.
"I feel like I used to and I have started to fire now," said Millar, who plans to race in the Tour of Spain.
"Once I have rested for a few weeks, I will be back to my best, and next year I will be better than ever."
With no race preparation, Millar failed to achieve his objective of a stage win but took great heart from his performance ahead of the Tour of Spain, which starts on 26 August.
"I didn't doubt I would finish the Tour, despite the fact that I was sick at the beginning," added the 29-year-old, who finished two hours four minutes and 10 seconds behind winner Floyd Landis.
I haven't done this for two years and I'm still really looking for my race fitness
"I've never had any problems. Keeping in the race is more a state of mind. It's not rocket science, you just have to look after yourself.
"But I haven't done this for two years and I'm still really looking for my race fitness.
"In a way, I haven't even really been part of the race. I was an also-ran. I was even finding out the results of what happened in the evening on television!"
Millar was not the only Briton to make it to the Champs-Elysees. Olympic individual pursuit champion Bradley Wiggins also finished the race.
It is the first time two Britons have completed the Tour since 1993, when Robert Millar and Sean Yates both reached Paris.
Wiggins has not enjoyed being unable to compete for stage wins
But Wiggins, unlike Millar, was not so upbeat after finishing 123rd, three hours 25 minutes and 13 seconds back from Landis.
"I've ridden the Tour, which was a childhood dream, and at the moment it feels like the sort of thing you do once because it's so bloody hard that you can't envisage doing it another year," said the 26-year-old.
"I've told the team I'll never ride again, but what I mean is that I don't want to come back again just to be a participant.
"I need to go away and think about whether I can be competitive in the Tour.
"I've gained a lot of confidence in terms of what I can achieve and I'll be interested to see what kind of improvement I make physically.
"There haven't been any low points, apart from the prologue where I thought I'd be closer to the win than I was.
"And as a physical test it hasn't been evil; it wasn't horrible at any time. I've felt more and more tired but never felt physically out of it."