Manchester United striker Zlatan Ibrahimovic understands he is entering the final years of playing at the highest level, manager Jose Mourinho said.
Ibrahimovic, 36, made his return from a serious knee injury earlier this season and has featured seven times in all competitions.
However, the veteran has started just twice and scored one goal, with the 2017-18 campaign appearing set to be Ibrahimovic's last at United.
Mourinho believes Ibrahimovic can still perform at the top level, although he said the striker was nearing the end.
"I was his manager when he was 29 at Inter Milan. We can't stop time, and for players time means a lot," he told UK newspapers.
"Zlatan knows that. He knows that at the highest level he's in the last part of his career, but his dream, his desire, his fight was always to end at Manchester United his career at the highest level.
"And, using the words he repeats all the time, being useful for me, for the team, and that I think he can. 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, as a quality player on the pitch, I think he can do that, he deserves that and I'm here to try to help him do that."
United, second in the Premier League, host Stoke City on Monday.