Player’s condition without plsying??

I just notice that 1 of my players trained this morning after training he was 93% condition...

I played a match, he did not play because suspended with a red card... and now he is 86%..

What is happening???

I play to relax so sometimes I don't pay much attention to the physical %, but I have to admit that there was a time when I saw a player without playing and his health dropped to 85%, which was strange. I thought I remembered wrongly, but seeing you ask, I'm sure I'm not the only one experiencing this. I don't know how the game calculates it secretly, but I hope the publisher will explain clearly so I can plan a reasonable recovery. Among Us Online