Downing five-times champion Venus Williams and 2017 semi-finalist Magdalena Rybarikova, the 15-year-old, known as Coco, has made waves at the All England Club, playing a fearless brand of tennis that the Swede says belies her age.
"It's inexplicable that a 15-year-old can get this far without losing a set at this level," Wilander, now a tennis analyst for Eurosport, said.
"At 15, her movement shouldn't be that good because physically she shouldn't be as strong as she is, but she flies. She's quick and she covers the court.
"She is strong in the outer parts of the court, so you can't really push her into playing defence. Cori is really 18 or 19 years old physically, I think she's a super athlete at a very young age."
Wilander said Gauff did not get nervous on court against players far more experienced than her because she has nothing to lose at such a young age.
"You look at players who came on to the scene when they were 15, (Steffi) Graf, (Martina) Navratilova etc, and they are women who went on to win multiple Grand Slams," he said.
"If you ask me my opinion on Cori, yes, she is a superstar for sure.
"Unless there is someone who stands in her way – and by that I mean, it could be a trainer, an agent, a boyfriend or even a parent. It could be someone there who stops her natural growth. Otherwise, for sure she will be top five in the world in five years."
Her parents have been cheering each winner from the players' box, keeping her feet on the ground with the advice to keep it simple and that the tournament is not yet over.
She is due to play her third-round match against Slovenia's Polona Hercog on Friday on Centre Court.
(Reporting by Rohith Nair in Bengaluru; Editing by Alison Williams)
