Two men on your panel have the same toughness rating. One of them plays
sixty matches without missing a Sunday. The other pulls a hamstring in
April, comes back in June, and pulls it again in July.
That is a different quality from toughness, and the game now models it
separately. Toughness is whether a man takes the hit on the day.
Constitution is what the same hamstring does across a career. Roughly
one man in twelve is glass, one in twelve is iron, and the rest are
somewhere in between.
You are never shown a number for it. Your physio gives you a word, and
only once your selectors have watched the man long enough to have an
opinion. A stranger called in from a club is a stranger in this as in
everything else.
The reason it matters is selection. A prone player is not a bad player.
He is a player you plan around: you rest him in the league, you do not
ask him for three matches in nine days, and you make sure somebody
behind him has learned the position. That is a real decision, which is
the only kind worth putting in a management game.
Also in this build: you can now put two players side by side and compare
them properly, with the same honesty rule applied. Exact figures compare
against exact figures. A scouted stranger compares as the range your
selectors actually believe, and nobody gets the nod on a guess.