New England Patriots tight end Rob Gronkowski hangs out of a duck boat as fans cheer during a parade in Boston, Wednesday, Feb. 4, 2015, to honor the NFL football team's victory over the Seattle Seahawks in Super Bowl XLIX in Glendale, Ariz. (AP Photo/Charles Krupa) AP

The retired tight end had to quickly improvise when his Fox Sports co-hosts asked him about an NFL player who doesn't exist

Rob Gronkowski may be one of the greatest NFL tight ends ever, but as a rookie on "FOX NFL Sunday" last year, he had to endure some hazing.