For the Barcelona attacker, that meant he had to have his diet down pat.
But the Argentinian star wasn't always eating like a professional. The Daily Mail previously reported about how Messi's eating habits were something you'd expect from a couch potato rather than the best player in the game.
As a teenager, despite his incredible potential and already established reputation, Messi was more a fan of fast food than fresh fish.
Several urban legends have done the rounds about just how bad his eating habits were: before a match during the 2008-09 season, Messi reportedly interrupted a Guardiola team-talk to ask if he could quickly grab a soft-drink while there are also reports that the Barcelona coach had to have a vending machine removed from the stadium because it was too close to the dressing room.
So how did Messi overhaul his diet to become football's GOAT?
He teamed up with Italian nutritionist Giuliano Poser in 2014 who explained just how bad his junk food diet was for his recovery. And with such a hectic schedule (some games just three days apart) being 100 per cent was crucial to maintaining high levels of performance and avoiding injuries.
Poser's advice was to exchange sugar-loaded foods with salads and seeds, fresh fruit and nuts. Messi also slowly reduced his meat intake - there are some suggestions that the body has to work harder during digestion on a carnivorous diet.
He also turned to tea to quench his thirst.
"Vegetables, seasonal fruits and a good mineral water are essential fuels for our muscles. You have to reduce the intake of processed foods or foods contaminated with pesticides, herbicides, antibiotics, medications..." he told Corriere del Veneto.
"And, of course, alcohol, tobacco and foods that are not tolerated. Football players often pay the consequences for bad nutrition."
After the 2014 World Cup, Messi returned to club duties with his new diet underway. The results were immediate. He led Barcelona to the treble after shedding three kilos. At 5 ft 5', Messi weighed in at 67 kilograms.
Interestingly, his diet also played a huge part in staying on the field. Between 2006 and 2013, Messi suffered 11 injuries. Following his nutritional changes, Messi spent significantly less time on the sidelines.
With more responsibility on his shoulders, Messi began working with the Barcelona nutritional team led by doctor Maria Antonia Lizarraga Dallo to reduce travel time.
But the advice has stayed the same: stick to fresh produce.