The Lineup Assistant automatically designates players as must-bench players if they are injured and are ruled out or are not playing for any other reason during the selected timeframe. 

You can change who is designated as must-bench players by:

1. Clicking on any player in the "Which players are your must-bench" section and selecting who you want to be your must-bench players. 

2. Then selecting or deselecting which of your players you want to be designated as must-bench players. 

3. Once you're done, click on the blue "Select" button.