Playing friendlies with 0% condition

I'm wondering if it's possible to play with 0% condition.
Do the players get automatically substituted? What if there aren't subs?
Do they receive skill points?

(Basically I'm wondering if it's possible to gain skill points without condition loss)

As I remember, there is no forced substitution, but the tired players are more likely injured. I'm not sure about sp because I didn't concern training progress of those players.

A player can not play if his condition is under 30% if you dont have enough players to play the match will be cancelled and you will lose 3-0

I was asking about friendlies.
I played with half team at 0% - they don't receive skill points.
They probably are more likely to get injured (i played multiple games with 4 players at 0% and received one injury)

the gaining of a player, in games or training too, cause a relative condition loss.
If you haven't any condition to loose, you gain nothing.