Arguably the greatest player to have played the game, Lionel Messi has been a sensational footballer for quite some time now.The Argentina international has won six Ballon d'Or awards, the most in the award's history. His most recent one came in 2019, when he pipped Liverpool centre-back Virgil van Dijk and Juventus attacker Cristiano Ronaldo to secure the Ballon d'Or.But since then, there's been a variety of reasons as to why the 2019 Ballon d'Or could potentially be Lionel Messi's last. We look at the:4 reasons why Lionel Messi could never win the Ballon d'Or again.#4 Lionel Messi's ageFC Barcelona v SD Huesca - La Liga SantanderWhile Lionel Messi continues to be one of the best players in world football, there comes a stage in every sportsperson's career when a drop-off is inevitable.Lionel Messi is Barcelona's most important player, but at 33, it cannot be expected that Messi will go on forever. Having made his debut for Barcelona in 2004, the Argentine has been a consistent presence in the first XI since then, and also shoulders the additional responsibility of being the club's star player who is targeted by every opposition defender.Lionel Messi extends his La Liga lead with 29 goals this season 🔥Legend 🐐 pic.twitter.com/dV8KoGocfe— ESPN FC (@ESPNFC) May 11, 2021So many minutes on a regular basis tend to wear a player down. Probably the most famous example in recent years is Alexis Sanchez, who failed to replicate his Arsenal form at Manchester United and looked like the shadow of a player he was for the Gunners.Lionel Messi's quality is undeniable and what he means to the sport of football cannot be underestimated. The forward's fitness levels are commendable, and his performances this season for Barcelona have once again shown his world-class ability. However, the body can only take so much.#3 The emergence of Kylian Mbappe and Erling Braut HaalandBorussia Dortmund v Paris Saint-Germain - UEFA Champions League Round of 16: First LegThere have been debates among football fans as well as critics as to whether the Lionel Messi-Cristiano Ronaldo era is coming to an end.The emergence of Paris Saint-Germain's Kylian Mbappe and Borussia Dortmund's Erling Braut Haaland has been the genesis for this debate. Both young forwards have been in impeccable form this season and already enjoy superstar status in the game.With both Lionel Messi and Ronaldo in their 30s, it has been suggested that Mbappe and Haaland are ready to take over their thrones. Mbappe has made 168 appearances in all competitions for the Ligue 1 giants and scored 129 goals. The 22-year old has already won the FIFA World Cup with France and played a key role as Paris Saint-Germain reached the finals of the Champions League last season.Make that 39 goals in 39 games for Erling Haaland now this season. 😳 https://t.co/owpRHk5bDV— Squawka Football (@Squawka) May 13, 2021Haaland, on the other hand, is one of the best strikers in the world despite being only 20 years of age. He has made 57 appearances for Borussia Dortmund and scored 55 goals, and has been linked with big-money moves to Manchester City, Manchester United, Chelsea and Real Madrid.With these two attackers already regarded as two of the best in the world, the Lionel Messi-Cristiano Ronaldo era of dominance might soon come to an end.Also Read: Lionel Messi or Cristiano Ronaldo? Best male footballer of the decade announced