@LeManiaque
comments are cosmetics, for the realism of the game.
It's like ass. man comments - lol
I 've seen a comment "he 's not happy about it" a sub for an injured player.
or I made a sub in 5' min (I decided to change my tactics) and the comment was " great game for X player"

Condition :
well, this is an important factor.
The old times, 2 years ago, before the live rates, an experiment manager could find out who of the players was under-performing and sub him.
We 're talking when comparing players with the same position (Defenders, 2 MC, 2 wingers, 2 ST).
The player with less condition loss was the "lazy" one, the guy who got lower rate after we could see it in match report.

So, more active > more condition loss > better rate.