The 34-year-old Swedish striker scored the only goal of the contest as Manchester United defeated Zorya Luhansk 1-0 in the Europa League at Old Trafford.
The goal was Ibrahimovic's sixth in 10 appearances for the Red Devils this season but it is more than just his scoring feats that prove his worth to Mourinho's side.
"He is a tremendous player," the Portuguese told MUTV.
"Even if he doesn't score goals, the dynamic he gives to the team, the movement, the leadership and attacking organisation.
"Nobody can believe his age. What matters is the quality, and the quality is amazing."