Maybe there's an alogrithm... but I think, there are some other things, like a randomfactor, what this season, next season,... will be high.

Last season I had the fewest games since beginning, but got most cards of all seasons, but only few injuries. So I had ~100 red packs at the beginning of this season. This season, I got only ONE card until now, but nearly every game, I suffered an injury - and not the short ones. Longest was 21 days, shortest 9. There are only 9 redpacks left. -.-

The interesting thing about that: At important/close games, the injuries came in first 20'. At "normal" games, the injuries came at 75' or later. In this case, I had two f*cking troll games this season. Best player sufferd an injury at 13', my squad was the much better team (in Q and at the game: 2-8 shot on target), lost 2:0.
Nearly the same at 2nd leg of Cup: My best player from first leg (won 3:0, he scored 2 goals, assisted 1) shot 1:0 at 14', suffered an injury at 19'. His sub was rated with 6.2 - finally lost the game 1:2. But overall my squad was the better team again...