Many doubted whether they would see the striker play football again after he suffered a serious knee ligament injury back in April.
But he has miraculously returned to action after just seven and a half months, featuring from the bench against Newcastle United and FC Basel.
And Mourinho, speaking ahead of this weekend’s clash with Brighton and Hove Albion, revealed that he would look to give the 36-year-old more game time.
“He’s always here, he’s always positive, he’s a good influence,” he said. “It doesn’t change the fact he’s playing or not playing.
“That is important on the pitch because he’s one more option for us and I think it’s impossible for [Romelu] Lukaku to play every match, so we need this second option – another man, another striker.”
“No, he’s not ready, Step by step, minute by minute, match by match. He’s not a player that you play only if the team is losing or only if the team is winning.
“He’s a player that’s easy to bring in to the game, so normally he’s going to have these periods of 15-20 [minutes] and, one day, we will feel that he’s physically ready [to start].”
You could forgive Zlatan for taking a few games to rediscover his range in front of goal. He is, after all, still some way from full fitness and has never endured such a protracted spell on the sidelines before in his glittering career.
But there have been moments, flashes, to suggest that the giant is finding his touch already: an overhead kick against Newcastle that nearly snuck in at the near post and a last gasp header which sailed just over the bar against Basel serve as quiet indicators of Zlatan not meeting too much time to reassert himself in front of goal.
Supporters will desperately hope to see him handed another chance to impress during the latter stages against Brighton.