Hello @Zachary Whyte
Started new save with default database and default skin. Chose Fullham and quickstart option. Arranged friendly for u21 team on the same day as first team friendly. Arranged for 4 players to be available for u21 teams for 90min. In the mail before match, that told me about fixture clash chose those 4 players for u21. On the day of the main team match since GK was injured i place GK in the main team, other players were out of team completly. Next day after the game checked u21 team match and none of 3 chosen players took part in it... I uploaded save on ur cloud with the name fullhamtest.fm