Kylian Mbappe told Paris Saint-Germain on Monday that he would not be taking up an option to extend his contract until 2025, raising the spectre of him following Lionel Messi out of the club this summer. The 24-year-old France striker's current deal expires at the end of next season, with the option of another year. If he does not sign, the French champions risk losing him for nothing in a year's time -- so they could now sell him this summer rather than miss out on a windfall for one of the world's best players. Mbappe's decision not to renew, announced in a letter to the club and revealed by the French sports daily L'Equipe, is a fresh blow to PSG following the loss of Messi to Inter Miami.