Spanish footballer Sergio Ramos calls out UFC star Conor McGregor; The Notorious One responds

Spanish football star Sergio Ramos may have just called out Conor McGregor on Instagram.

The Real Madrid skipper, who is recovering from a hamstring injury, posted a video of himself flexing during a workout on Instagram, and then tagged former two-division UFC champion Conor McGregor:

"When you're ready, @thenotoriousmma," Ramos' caption read.

Of course, this was just friendly banter between the two sporting superstars. Conor McGregor responded in kind, telling Ramos to 'stay ready':

"Stay Ready, my brother Sergio! We have a big fight coming up"

McGregor was obviously referring to his upcoming lightweight rematch against Dustin Poirier, which is set to headline UFC 257 in January.

With reigning UFC lightweight Khabib Nurmagomedov announcing his retirement at UFC 254 back in October, the UFC may soon need to find a new ruler at 155-pounds, and the McGregor-Poirier matchup will likely have huge title implications.

Ramos, meanwhile, continues to rehab as he hopes to be able to re-join Real Madrid in their UEFA Champions League campaign soon. Real Madrid currently sits third in Group B, with 2 wins, 1 draw, and 2 losses for 7 points in five matches played.

Sergio Ramos and Conor McGregor have a long history of playful banter on social media

This isn't the first time that Conor McGregor and Sergio Ramos have interacted on social media. In fact, the two have been said to have a budding 'bro-mance.'

The back-and-forth started back in July, when Ramos showed off his version of the 'Millionaire Strut', which was made popular by McGregor:

"What do you think, @thenotoriousmma?" Ramos said.

Not to be outdone, McGregor responded by posting a video of himself scoring a goal:

"What do you think @sergioramos?" McGregor replied.

McGregor's football striking prowess earned him a training session invite from Ramos, which he graciously accepted should he get to visit Madrid soon.

For now, McGregor will have to keep his focus on the task at hand, and that's to defeat Dustin Poirier at UFC 257 in January.