What is the ruling when Team A's coach decides not to start F1 after the pregame conference?

When the coach of Team A decides not to start F1 after the pregame conference, the ruling allows F1 to be replaced without penalties. This is because, prior to the start of the game, the coach has the discretion to make adjustments to the lineup without incurring any consequences. Since F1 has not yet begun participating in the game or faced any batters, the coach is not obliged to keep F1 in the lineup and can replace them with another player without any penalties or restrictions.

The ability to modify the roster prior to the first pitch is an established rule, which helps maintain flexibility in coaching decisions and allows for tactical adjustments based on various factors, such as player readiness or strategy.