The 36-year-old Swiss marvel continues to defy the aging process, claiming his 20th Grand Slam title and sixth Australian Open crown in January.
He has enjoyed a perfect start to 2018 by winning both events he has competed in and taking his career singles title tally to 97.
"He shows there is no limit," said third-seeded Grigor Dimitrov on Wednesday.
"He keeps on proving it every year on the tour."
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He also won this tournament three straight years beginning in 2004, and in 2012 as well as last year.
Federer comes into the elite event as the oldest ATP Number One in history. In the Open era, only American Jimmy Connors has won more titles than Federer, with 109.
Federer has played two tournaments this year and won both -- the other being the Rotterdam Open.
"For me to stand right here as world Number One in San Jose is very, very special for me," Federer said at a charity event in San Jose, California on Monday.
Serbian Novak Djokovic, who is making his first return to the Tour since the Australian Open, is also a five-time Indian Wells champion and would like nothing more than to announce his return from an elbow injury by going all the way.
Both players are in opposite halves of the draw so they would not meet each other until the final.
Djokovic won Indian Wells in 2008, 2011, 2014, 2015 and 2016.
Djokovic, who is seeded 10th, has a bye and will face the winner of a first- round match between two qualifiers in his opener.
Del Potro, who made the Indian Wells final in 2013, said Wednesday he is healthier than he has been in years and full of confidence from his Mexico success.
- Del Potro confident -
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Del Potro defeated the hard-serving Kevin Anderson 6-4, 6-4 in the final to claim his first title of 2018 and post his seventh-straight career victory over Anderson.
The 29-year-old del Potro recorded his 21st career ATP title but this is one of his biggest in years and the earliest he has hoisted a trophy since the 2014 season.
His tough draw in Acapulco should serve him well this week.
If del Potro gets through his opening second-round match as expected, he will likely face Spaniard David Ferrer, whom he also had to beat in Acapulco. Besides Djokovic, that quarter of the draw includes Japan's Kei Nishikori, second seeded Marin Cilic and American favourite John Isner.