You start producing red blood cells as soon as you get to higher elevation. But they probably only acclimated around 1500 ft so far and would need a few more days to ready for a game. In fact when I go to high elevation, the first thing I notice is that I don't sleep as well. Would have been better to let them sleep well at a lower elevation somewhere and then fly in for the game. Whoever thought of putting this in the middle of the season really wasn't thinking.