It is ideal to keep continuous action while making an appeal for a runner missing a base. But if time is called and the pitcher must start the appeal from the pitching rubber, he is not required to disengage from the rubber to throw the ball to the base. If the pitcher balks during the appeal, he will lose the right to appeal.
If the pitcher throws the ball out of play (dead ball territory), the team loses its right to appeal. Also, if the pitcher he appeals from the rubber and fires the ball into dead ball territory (DBT), the runner/runners would only be awarded one base since he is appealing as a pitcher. If the appeal is made while off the rubber, and the pitcher throws the ball into DBT, all runners would be awarded two bases since he is throwing as a fielder.
Insider Reports: Balks and Appeals
The appeal process is sometimes tricky and occasionally even major league umpires get it wrong. In a game on September, 14, 2015, Rangers’ pitcher Cole Hamels was called for a balk he didn’t commit. Read about this play and understand the rule with the help of this Insider Report.
Bad things can happen during an appeal made from the rubber. Learn the details from this excellent Insider Report from Rich Marazzi.
This is a great explanation of how to follow the progression of a play that ensues right after a balk. It from a real quiz and discussion at the Brinkman Umpire School.