The Brazilian was handed his debut in the Europa League Group J game against LASK and made a good impact, creating two goals in a 3-0 win in north London.
Mourinho was enthused by his debut and says he can be more than just a deputy to Kane.
"Of course left-footed there are not many centre-backs with a left foot. Some clubs have them but the majority don't.
"To have him as an option is also good because to attack, the build-up is also important."
LASK were never in the game and their head coach Dominik Thalhammer knew the task was too big.
"It is a Champions League team, so our view has to be realistic," he said. "You have to recognise there is a gap between the two teams. You can't expect to come here and win, Tottenham are a top team with fantastic individual players."