That is extremely lucky. I can get 2 injuries in just one game alone. My players are in full condition / moral in almost every game. Injuries are pretty much random. Unless you overtrain your players or do a lot of friendlies. You are still low level, so don't expect to get this little injuries all the time.
I have no complaints about injuries now. I used to get about 20-30 injuries in one season. I think it has reduced to about 10-20 injuries.