Both men are fans of the sport and celebrated with their mutual friend Kell Brook following his win over Amir Khan last month before promising to visit the Ingle Gym in Wincobank where he is based for a training session.
Windass was first up on Wednesday evening and was put through his paces by Amer ‘Killa’ Khan, one of the gym’s trainers.
"He was actually alright,” said Khan, a former unbeaten professional boxer who was coached by the late Brendan Ingle.
"I was quite surprised, he’s got a couple of moves and he’s in great shape.
"He said it’s completely different to football, the fitness side of things, and he’s a really fit guy.”
"He’s a really nice guy and is in fighting fit shape.”
Former Glasgow Rangers forward Windass has been in red-hot form on the pitch when available for the Owls this season with four goals in just seven league appearances.
He is currently working his way back to full fitness, having endured an injury-hit campaign, and was joined for the training session by his brother Jordan, who plays for National League North side Bradford Park Avenue.
Khan sent a photo of Windass at the gym to Sharp – and received quite the reply, which should be taken with a larger-than-usual pinch of salt.
“He said: ‘Me and Josh in a big fight at the end of the year!’.
"I really like Billy, it will be interesting to see what he’s like in the boxing field.
"Josh has got the age advantage but Billy has got the experience. They have already got their own corners sorted – red and blue.”
Numerous celebrities and former sports stars have turned their hand to boxing in recent years, from Freddie Flintoff and Rio Ferdinand to YouTubers such as the Paul brothers, Jake and Logan.
Though with Windass and Sharp – who has been directly involved in 21 goals for the Blades this season - still doing the business on the pitch, the chances of them meeting in the ring any time soon appear slim.
"This could be a sell-out at Sheffield Arena for the city’s bragging rights,” said Khan.