Talk Fantasy Football

This question may have been asked here before, but on a quick glance I was not able to find answers.

Say a player with pass block skill is prone, but between the thrower and the catcher when the ball is thrown. Can he use the three extra MA to stand up? Also should he have jump up skill could he get up and still move the three extra MA?

No. Pass Block allows you to move 3 squares - it does not give 3 MA. So you can't use it to stand up.

Jump Up can only be used at the start of your own action.

No you can not, and jump up only works in your team turn...