Roma may not be the youngest team in the league, but they have an abundance of youth where it counts (and concerns) most: in central defense. Apart from the midfield maestro, an argument could be made that the most mentally taxing position on the pitch is center-back. While these players are typically seen as lumbering beasts, more akin to mountain trolls than wisened scholars, a top-end center-back needs to be able to read and diagnose an attack in the blink of an eye.
These defenders can dissect an attack as it unfolds, accounting for, and in some cases predicting, a myriad of offensive permutations, including passing combinations, off the ball runs, which players are a threat to shoot—and with which foot and from which location—which players are likely to cross, and so on. And they have to do all this while possessing supreme spatial awareness, knowing where they are relative to their fellow defenders, the keeper, the officials, etc. And once they've mastered that, they have to think and react quickly enough to jump-start a counter attack.