3. Marquinhos

Age: 19

Nationality: Brazilian

Club: Paris Saint-Germain

As the fifth most expensive teenager of all-time and fifth most expensive defender of all-time, it would be a shock not to see Brazilian centre-back Marquinhos on this list.

The youngster joined PSG from AS Roma for a staggering €31.4million fee last summer but has struggled to displace his compatriots Thiago Silva and Alex thus far.

Although at 19, he has plenty of time to reach his massive potential.

Manchester United
Premier League