Without wanting to defend all of our players as some aren't at peak fitness, this was what immediately came to mind: explosive sprints; rapid changes of direction.I see where your coming in terms of stamina. I went to see on business the developers who write the software and own the rights to the vests worn during training.
My days the stats are something else. Doing 100 percentage bursts are not same however as the above and requires another type of stamina all together which pro footballers require.
Covering miles and miles during 90 minutes I salute them. Injury's are going to happen end of but it's down to the medical and fitness coaches to ensure a proper warm down and close monitoring especially after match days
Personally, I can happily cover the distance that most footballers cover in 90 minutes, yet a relatively short sprint at full power will quite quickly deplete my energy.
I've felt more exhausted after a slightly over five minute full-pelt run, with some contact at the end, than I have after an hour run at a good pace - it's different.
Players have to train their bodies to be able to have the stamina to run for an entire match and still be able to sprint, tackle and challenge for short periods of time.
Saying that however, I do know the physical fitness in other sports (hokey, athletics etc.) is much greater than some of the so called athletes in our sport.
I think there is still a fair way to go with some players, and those small gains could/are the difference between wining and not.