"It would be something to see, right?" Lewis told TMZ Sports.
Lewis, 33, was released by the Jaguars in March. He said it's unlikely he would ever take a professional fight but does plan on training on a more full-time basis once his football career ends. The UFC's Tyron Woodley said Lewis has the ability to compete in a pro MMA fight.
The 2010 Pro Bowler was among the early adopters of MMA training as part of his football workout regimen.
Hardy, 29, began an MMA career after going unsigned during the 2016 NFL season. He has won his first three fights via knockout, including a 14-second win over Ryan Chester in February at LFA 33 in Dallas.