WTA Insider podcast host Courtney Nguyen said she was a lock for the top 10 most important women in tennis history.
Rothenberg quickly bit and named his top 10.
There were expected names like early 20th-century champion Suzanne Lenglen, African-American pioneer Althea Gibson, Billy Jean King, Chris Evert, Martina Navratilova, Steffi Graf, Monica Seles, Serena Williams and Li Na.
But there was one name that surprised audiences — former Russian star Anna Kournikova.
While Kournikova was one of the world's most known tennis players, it was less for what she did on the court and more for what she did off it.
Although she never won a singles title, she reached number eight in the world, but she did have success in doubles, reaching world number one and winning Australian Open titles with Martina Hingis.
However, more important for her influence, Kournikova ushered in the new era of marketing and sponsorship.
The fact that she retired from the WTA in 2003 at just 21 after a string of injuries, only staying active in exhibition and team events but still maintaining her name recognition is a testament to her star power.
Rothenberg clarified his position, arguing there's a difference between importance and performance.
With Kournikova's success off the court, it's hard to argue with how she changed the sport and led to a new wave of empowerment for professional women's tennis players.
This has led to the modern social media influencer style of sportsperson, including Eugenie Bouchard.
"Construction workers were watching tennis, business people were watching tennis. It wasn't just normal country club corporate clients that were watching tennis now," Ken Merritt, who coached Kournikova at tennis coach Nick Bollettieri's famous Florida Academy, explained in a 2015 interview with CNN.
"Women's tennis had a lot of TV deals after she was playing. There's a lot of things Anna did for the sport that went well beyond the box scores of wins or losses."
The 37-year-old Kournikova has also been dating pop star Enrique Iglesias since 2001 when she starred in his video for his song Escape.
The pair also have twin children and lead a relatively private life.
That was until Inglesias revealed a fair bit in an interview with The Sun late last year.
"It's probably more sex now than ever — the sex has not diminished," he said.
"Like any couple, you still go through your ups and downs and it's not always perfect.
"But it is perfect in a way. It's incredible to watch her be such a great mother.
"It's incredible to watch a mum do what she does, when a mother's instinct kicks in."
The debate was fierce on social media.
