A total of six of the Blues’ League One squad are aged 21 and below, with Dane Scarlett and Josh Griffiths regular starters in the league.
After switching recruitment to focus on signing players who are under 23, Cowley has prioritised the development of his emerging stars.
Indeed, Pompey boast some of the best young talents in the division, with Spurs loanee Scarlett tipped to have an outstanding career following an impressive start to his Fratton Park career.
We’ve taken a look at Transfermarkt’s estimated values to see who they believe warrants inclusion into the most expensive League One starting XI using players under-21.
Here’s which of the Blues’ crop of youngsters make the squad.