Zlatan Ibrahimovic, 35, who is Red Devil's top scorer having netted 16 times in 25 games, including 10 in his past nine, and in November Mourinho stated he intended to exercise the second-year option on the contract the Swede penned in the summer.
His future may well be at Old Trafford and, beyond that, Mourinho does not expect the well-travelled striker to bow out with a lucrative stint in Major League Soccer or the Chinese Super League.
"I'm really happy for him,'' Mourinho said of Ibrahimovic. "Maybe some people could think [he was] a top scorer but not any more at 35 years old, not any more because the Premier League is not Ligue 1. But for him, 35 is the same as 25, Ligue 1 is the same as the Premier League.
"He scores goals, he plays well and I'm really happy for him because he will end his career on a high, which is amazing. He's not ending his career in America or in China, he's ending his career at the top of the top.
"I'm really pleased with him. His record is good and he can improve. With no penalties, which is amazing too because normally the other guys that are top scorers around the world, they score a lot of penalties. He has had one penalty in 17 Premier League matches so I couldn't be happier.''
Meanwhile Mourinho, who has guided United on a 10-game unbeaten run, insists he has been comfortable embracing the task of taking charge of one of the world's biggest football teams.
"For me, it was easy -- it's a difficult job but easy to feel at home, easy to feel good in the club, easy to feel that the club wants to progress, the people want to be happy again,'' he added.
"I felt good immediately so five, six months here, but really feeling at home; for me it was quite easy.
"Obviously expectations are high, results... up and down and we are in a position that is not the position where we want to be. But in terms of passion for my work, passion for my new club, I'm feeling really happy here, yes.''