Messi's contract at FC Barcelona is set to expire at the end of the current campaign and, having fallen out with the club at the start of the season, the six-time Ballon d'Or winner is widely expected to leave once his deal is up.
The situation surrounding the Argentine star has caused many of Europe's leading sides to take notice and the likes of PSG and Manchester City have been identified as favourites to potentially secure his signature.
Both clubs had remained mostly mum on the situation until Tuesday morning, when Leonardo hinted that PSG would be quick to move for the 33-year-old in the event that he became available to sign.
"Great players like Messi will always be on PSG's list," he told France Football. "But this is, of course, not the time to talk about it or to dream about it.
"But we are sitting at the big table of those who are following the case closely. In fact, no, we're not yet sitting there, but our chair is reserved, just in case...Four months is an eternity in football, especially at this time."
Messi has spent his entire career with Barcelona, where he has scored an incredible 648 goals in 753 games and won no fewer than 32 major honours.