There aren't many players who can say they have a winning record over 20-time Grand Slam winner Federer but Delbonis is one of them.
In their only other ATP meeting in 2013, Delbonis won on clay in Hamburg 7-6 (9/7), 7-6 (7/4).
Delbonis, who is ranked 67th in the world, is no stranger to upsets in Indian Wells. In 2016 he shocked world number two Andy Murray to reach the fourth round.
He reached the second round here this week by saving two match points to defeat another American Ryan Harrison in three sets.
Federer, who regained the world number one ranking last month, is on a quest to make history in the California desert by winning an unprecedented sixth Indian Wells title.
The 36-year-old Swiss marvel continues to defy the ageing 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.
Federer told reporters on Thursday that he won't be taking anyone for granted in this draw.
“I didn't come here to lose in the first round two and two,” he said. “I care about the moment. I care about the results.”