I think with Sam and Cap there’s never a question of how far they’re willing to go because they take care of each other, they look out for each other and they believe in each other. I think Sam becoming an avenger and Sam being on team Cap is not because of his relationship with Cap but because of what happened in Captain America: Winter Soldier. He literally, when fighting SHIELD, lost all of his faith in these government agencies because it was infiltrated by HYDRA. So you never know when someone has your best interests in mind and he knows Cap does. – Anthony Mackie