Federer goes into the ATP World Tour Finals, which begin in London on Sunday, in the unusual position of not being the sport's pre-eminent force after a relatively unsuccessful year by his high standards.
Although the Swiss star started the season by winning the Australian Open, he lost his grip on the Wimbledon and French Open titles he won in 2009 and failed to return to the US Open final.
Even victory in the annual end-of-season showdown between the world's top eight players won't change that as world number two Federer is nearly 4,000 points behind Nadal in the rankings.
The 29-year-old broke Jimmy Connors' record of 160 successive weeks as the number one in 2007, but he concedes there is little chance of reestablishing that kind of dominance if Nadal continues his current fine form.
Spaniard Nadal will take some stopping as he is on a hot streak after winning Wimbledon and the French and US Opens.
"Sure it is challenging (to get back to No.1). It is going to be very difficult because Rafa is playing well," Federer said on Friday.
"It's not something I have in mind right now. The goal is to play well here in London and prepare for next season and hopefully at some stage get it back.
"If not then I will focus on just winning tournaments. That is something I like doing as well!
"I have Australia to defend first. Rafa has no points to defend here, that's why things look very good for him for the next few months."
After a disappointing run at the Grand Slams this year, Federer, who opens the tournament against David Ferrer on Sunday, has regrouped over the last two months and arrives in London in decent form.
Like his rivals, he could be forgiven for feeling a little tired at the end of another gruelling campaign, but he is determined to ignore the aches for long enough to end the year on a high.
"Physically I'm fine as I predicted after playing the Paris Masters," Federer said.
"I feel like I've got one more tournament left in me. That has been my mindset for a long time. I know when the season starts and ends.
"I was never a bit complainer about a long season because that gave me more chances to take a break. If you were injured at certain times it gives you the chance to come back.
"My body is not screaming for a vacation quite yet. I don't want my mind to do that otherwise I won't be 100 percent focused on my matches.
"This is a huge tournament for me. It is a goal of the season to make it here. It is always fun to play my fellow top 10 players at the end of the season. I hope I can save my best until last."
As befits a player of his achievements, Federer is something of an old hand when it comes to the ATP Finals and this will be his ninth successive appearance in the event.
But there are still some moments that come with the life of a top player that prove both surprising and entertaining.
One such moment came for Federer on Thursday when he and the other seven competitors were invited to the home of British Prime Minister David Cameron at 10 Downing Street.
"It was an interesting trip, something you don't expect to do in a life as a tennis player when you grow up," he said.