Trophy workout! Tennis ace Venus Williams leads NFL superstar Rob Gronkowski in Instagram workout - with their TROPHIES (VIDEO)

Venus Williams and Rob Gronkowski joined forces on Instagram to enjoy a shared workout during the COVID-19 lockdown as the two sports superstars showed off their silverware while toning up for the return of live sport.

Three-time Super Bowl champion Gronkowski recently announced his return from NFL retirement, and was immediately traded from the New England Patriots to the Tampa Bay Buccaneers, where he'll team up with longtime friend and teammate Tom Brady, who also joined the Florida franchise during the off-season.

It means "Gronk" needs to get himself back into shape for the upcoming NFL season, and he had the perfect training partner in tennis star Williams, who put him through his paces as they worked out while holding their trophies.

Williams showed off one of her US Open trophies, while Gronkowski held the Vince Lombardi trophy awarded to Super Bowl champions.

As they worked out, Williams grilled "Gronk" on his trophy and how he won it, as the former Patriots star talked through the key plays that saw his now-former team capture the trophy in 2019 when they defeated the Los Angeles Rams.

Gronkowski announced his retirement not long after that win and dipped his toe into the water of becoming a professional wrestler with the WWE. But, despite capturing the WWE's 24/7 title only a couple of weeks ago, the lure of the gridiron proved too much as ha returned to the game with the Buccaneers.

Perhaps he's hoping he can bring a "Lombardi" to Florida and work out with a new trophy this time next year...