The Swede last featured for the Red Devils on Boxing Day after suffering a serious knee injury and saw his proposed return to action hampered by a hamstring strain.
That meant Ibrahimovic also missed Monday's 3-0 win over Stoke City, although Mourinho still has plans for the striker during the remainder of the campaign.
"Zlatan knows that, at the highest level, he is in the last part of his career," said Mourinho.
"But his dream, his desire, his fight was always to end his career at Manchester United, being useful for me, being useful for the team. That I think he can [achieve].
"He just needs to feel really happy with his knee, with his condition, and that I think he can.
"As a leader in the dressing room, as a leader on the pitch - he is a quality player on the pitch, he can do that and I think he deserves that.
"I am here also to try and help him do that."