The big Swede found the back of the net twice at the Hawthorns as helped Mourinho’s men claim all three points with his 15th and 16th goals of the season.
He’s played more games this season than any other Man United player and has played a vital role, with ten goals in his last nine games.
Speaking about his impact, Mourinho claimed he was not expecting to play him each game when he signed from Paris Saint-Germain in the summer.
“I was expecting in the Europa League to give him a different situation. But we put ourselves in a difficult situation by losing the first match at Feyenoord,” he said.
“Even the last one, we needed a point to qualify. But it is something I do with him. We communicate and change ideas about his situation and his feeling. Until now, he is feeling great.
“I was very lucky in my career. I have worked with many players with great enthusiasm. And I have players in the last phase of their careers and they are still magnificent in their attitude.”
Even though he went six games without finding the net in October, he has now scored 11 Premier League goals and boasts a record at 35 that no other player could.
He’s aged like a fine wine and although he’s in a top physical condition, it’s not wise to play him in every single game, even though he is in spectacular form.
The tough decision for Mourinho is finding when to give him a rest, and taking his current goal-scoring record into consideration, it won’t be easy.