Just like in any team, finding the perfect mix between experience and youth is a difficult balance to judge. Both have their uses and that is why countries tend to include players at each end of the spectrum.
Essam El-Hadary will be the oldest attendee of this summer's World Cup. However, at the age of 45 years and four months, it will be his first because Egypt hasn't featured in the illustrious competition since 1990.
He is a whole six years ahead of Rafael Marquez, who will be playing in his fifth World Cup with Mexico at the age of 39 years and three months. He became the first player to captain his country in four successive competitions so don't be surprised if he makes it five in Russia.
Sergy Ignashavic rounds off the top three. At the age of 38 years and 10 months, he will undoubtedly be the hosts' most experienced player this summer.
Alternatively, Daniel Arzarni (Australia) and Kylian Mbappe (France) will be the youngest participants at the World Cup. Both will be 19 years and five months when the competition kicks off on June 14.
They are joined by Nigeria's Francis Uzoho (19 years and seven months) in the top three. All will be playing in their first World Cup, hopefully out of many..