"I was like, ‘Ooh, Serena is back,'" Navratilova said. "So yeah, I think sky is the limit for her now. I wouldn't put it past her to win the whole thing."
Williams plays her third-round match Friday night against Ajla Tomljanovic.
Footwork is one of the areas Navratilova says can be improved through Sense Arena's virtual reality tennis training program that launches next month. It allows players to do drills such as returning serve and volleying, while swinging a racket that gives a similar feel of a real one, without the chance of injury from repeatedly hitting balls or running on hard courts.
Sense Arena has a hockey program used by five NHL and nine NCAA Division teams. CEO Bob Tetiva said having mastered the swing technology used in hockey made it natural to add tennis. The company, based in the Czech Republic, added Navratilova to its tennis advisory board.
The 59-time Grand Slam champion said she "whiffed" with her first few swings, but quickly got good and saw the benefits of being able to practice indoors or with an injury that limits the ability to run.