Teams often have their own secret info they use during games, such as play calls in football, batter signals in baseball, etc. When a player switches from one team to another, do they share all that secret info with their new team? Does the old team make any effort to switch things up so that the info the traded player knows is no longer valid?

Why Does The Quarterback Call Out The Mike In Football? | vIQtory Sports
The mike linebacker on defense is one of most important positions. The quarterback calls out the mike linebacker in football for many reasons. Learn why here!