The footballing world has been in shock since it was announced on Thursday evening that arguably the greatest footballer of all time, Lionel Messi, is to leave Barcelona as a free agent.Last summer, Messi spoke of his desire to leave the Spanish giants but stayed to play out the last year of his contract. The Argentine had a change of heart this summer and agreed to sign a new contract, but Barcelona's financial woes meant they couldn't afford to register Messi.The club blamed La Liga, instead of their own financial mishandling, in the statement made public on Thursday night this is a club who has spent over £300 million on the transfers of Phillipe Coutinho, Antoine Griezmann and Ousmane Dembélé.Fresh off the back of winning his first major competition with Argentina the Copa America Messi is now a free agent and Paris Saint Germain are scrambling to build a financial package to afford the little magician. According to The Telegraph, the implication could be selling football's hottest young talent: Kylian Mbappé.Mbappé is entering the final year of his contract in Paris and is rumoured to have told manager Mauricio Pochettino that he doesn't intend on signing a new deal leaving the 22-year-old a free agent next summer. Liverpool are a club who have been heavily linked with the signing of the French superstar, with the owners meeting Mbappé and his representatives on their private jet before Mbappé made the switch from Monaco to the French capital way back in 2017.Read MoreRelated ArticlesRead MoreRelated ArticlesMbappé has gone on to be crowned Ligue 1's top goal-scorer for three consecutive years and has won the title in three of his four seasons at PSG.PSG's star man was an integral part of the French World Cup winning side in 2018, adding even more pedigree to his household name. The French club made it to their first ever Champions League final in 2020 but lost out on Europe's most prestigious prize after losing 1-0 to Bayern Munich.Mbappé is the heir to Messi's crown, a sublime hat-trick at the Nou Camp in the Champions League last season proving this point emphatically. Although the youngster is still a little raw, he could go on to win multiple Ballon d'Or crowns.However, PSG are under pressure with Mbappé not ready to sign and implicitly threatening to let his current deal run down. Owner Nasser Al-Khelafi has been so stern over Mbappé's position that he recently stressed that PSG "will never sell him and he will never leave on a free." It was a slightly bizarre statement yet the tone was clear.Read MoreRelated ArticlesRead MoreRelated ArticlesWas this a warning to clubs after the Frenchman's signature that PSG would not be prepared to do business? Who knows. If Mbappé doesn't sign a new deal then PSG have no choice but to let him leave for free. With Messi now on the market, PSG's stance may change. Although Mbappé is a huge name worldwide and is the star of Nike, he isn't six-time Ballon d'Or winning Messi. The Argentine would bring a legion of millions of fans to any club he plays for, he would also bring a huge increase in merchandise sales.If Mbappé is certain about leaving PSG next summer, then maybe PSG will think it's wise to sell the Frenchman this summer in order to reap the rewards of signing Messi. FSG may be careful with their spending in the transfer market, but they are very good business people and will know that possibly capturing Mbappé will put Liverpool in a stronger position in the future on and off the field. Still wildly unlikely, it at least makes a lot more sense than a direct move to bring Messi to Anfield.His youth means there is resale value in the player, something FSG are fond of when signing a new player. Five good years out of Mbappé at Liverpool means he could still realise his dreams of playing for Real Madrid, but why not stop off at Liverpool first?Read MoreRelated ArticlesRead MoreRelated Articles