Ronaldo moved to Juventus earlier this summer on a four-year deal having previously starred at Real Madrid.
While in the Spanish capital, the Portugal ace had a competitive rivalry with Messi with the pair regularly battling for the La Liga title.
Argentina forward Messi has spent his whole career with Barcelona, breaking plenty of records along the way.
He’s the only player in history to score 40+ club goals in nine consecutive seasons while his five Ballon d’Ors have him level with Ronaldo.
Though Messi could soon leave the Nou Camp if Marco Tronchetti Provera, the CEO of Pirelli and long-time sponsors of Inter, is to be believed.
Tronchetti Provera has spoken to Tuttosport claiming that Inter’s owners Suning could launch a bid for Messi.
"I hope that Suning, once Financial Fair Play will allow it, can make a huge signing," said Tronchetti Provera.
"Messi? How can you say no to Messi?"
Inter have Champions League football again next season, so they could be in a position to make a move for Messi.
Whether the 31-year-old wants to leave the Nou Camp remains to be seen, though earlier this summer he reiterated his desire to stay at Barcelona.
"I'm not tempted to leave Barca, there is nowhere better than Barca. If I wasn't here I wouldn't be anywhere," he told TyC Sports.
"It's the best team in the world, the best city in the world, my children already have their friends. I do not need change.
"I fight to win everything, I do not need to go anywhere else to prove anything.
"I do not like seeing myself playing in old games, but I have incorporated a lot of new things into my way of playing.
"I feel good and fast, but when you're young you do it 500 times a game and today you select the games more."