If pre season can not be used to determine how a team is likely to perform when the new season begins then how are they able to know the players that are going to be starting in a game for the season? We understand the difference between the tournament and the pre season games but a player performance during the pre season is used to determine his performance in the league since the players performance in the training make the coach to start them in the match so I believe a player who is not feet during the training and pre season games will not be given the opportunity to start a match during the new season.
Maybe you are forgetting that before and even after preseason games these players does train and their performance are been seen during trainings, the essence of preseason games is not just about players selection and mk d you sime players can be selected at the beginning of the season to be among the starting XI but later for some reasons, health or otherwise you do not see them start games as supposed so beyond all of that is preseason games, it is mostly a time to get players ready again for the season in a real time space away from just training.