The midfielder set up Villa's equaliser against West Bromwich Albion in the play-off semi-finals on Saturday, before winning the penalty that Abraham converted to give his side a 2-1 victory.
Abraham said: "He is a fantastic player and you don't question why he is a leader. His ability says it all.
"He is a such a good leader as well. For us it is a massive bonus to have someone like Jack in the team. I don't think he ever runs out of breath – he keeps going.
"I always think to myself does he ever get tired? Someone like him gets the ball and he keeps going and keeps going.
"He always believes and tries to encourage everyone – even until the last minute. It is always nice to have that behind you."