I'm probably jinxing myself, but I haven't had an injury in over a week, - currently have 65 reds in the bank, (I generally get 1 or 2 a day for watching vids on Facebook, and from memory I've used reds to heal 3 bad (6+day) injuries this season, and I've let a couple of players heal naturally).

I use my full squad and try to only play people for 1 (or at most 1.5) games a day, keep my pitch and medicals fully developed, and use rests to put people into games at 95% rested or better. I never play someone the 1st match after they've recovered either.

Last season was a bit worse, the game decided to injure or suspend all 4 of my MCs the same day, around day 13, and I had a run of DMC/DC injuries near end of season.