Does a players development or game in general really take a hit if they missed the pre season team training camp due to injury

kai_123 Lakers1:40 pm Fri Jul 31 EDT Deleted

Even if the player was ready for opening day, I see many people using this excuse whenever the player is not playing up to standard throughout the entire season, that because they didnt attend training camp they did not have the opportunity to find their groove. Or is this just a myth? I thought the players would still be able to work on developing their games through in-season practices or workouts of their own.