unfortunately it is part of nordeus's shady financial strategy. They raise the likelyhood of injurys of key players at the start of the season, especially for teams that did well last season and reduce the free video boosters available to try and manipulate regular users into buying tokens just so they can field their proper squad. Unfortunately it works as they seem to raise the free boosters etc from videos near the last part of a season so that players start power training/buying decent players which keeps them interested in the game for the upcoming season before they hit key players with long injurys/dry up the videos when everyones playing knock out cup/CL games making users panic into buying tokens. My best suggestion is to try and buy some cheap old players during the beginning of the season that arn't too far below your starting squad and then use them against any team that looks abandoned/dead rubbers in CL if you are guranteed 1st before you've finished the 6 group stage matches.
I've had about the same number of injurys including my top striker/top amc/top mc and just got hit with a 10 day injury on my dmc. Not to mention the game that my striker got injured, he got fouled 4 times by an opposition player before the guy got red carded