The 35-year-old arrived in the summer on a one-year deal with the option of another season, although the make-up of that extension clause is shrouded in mystery.

On Friday, United boss Jose Mourinho said he was convinced Ibrahimovic would still be at Old Trafford when 2017-18 got under way, but the 20-goal striker is giving little away just yet.

Asked if he has triggered the extension clause with goals and appearances, the veteran striker said: "Something like that. I have to score 100 goals!

"The option is already fulfilled. But there's nothing done yet.''

When asked whether it was case of having to wait and see, Ibrahimovic said: "From my side. We'll wait and see. Let's see what happens.''

It would be a huge surprise if Ibrahimovic does not remain at Old Trafford given the way he has excelled this term.

But whenever the Swede does depart, he will do so having left a mark on fans and teammates that belies his brief time at the club.

United sources said at the start of the season that the players were standing taller next to Ibrahimovic and a number of his teammates have spoken about his impact.

Anthony Martial appears to be one of those benefiting from the well-travelled striker's knowledge and experience.

Having endured a difficult season and found himself watching from the sidelines recently, the 21-year-old marked his return to the starting lineup by setting up one and scoring the other as Watford were beaten 2-0 on Saturday.

"He's not going around with his head down,'' Ibrahimovic said of Martial. "He's positive, training hard and has a lot of energy. Obviously he wants to play.

"It's not like we go around to everybody and talk. It's about the moment, when the situation is there.

"When we eat breakfast he sits beside me and we talk. Everybody talks to everybody.

"It's not like you go to one and try to cheer him up. It's a good atmosphere, the guys are very professional. Positive vibes.''

Martial's reprieve, and more impressively that of Henrikh Mkhitaryan, should give out-of-favour Luke Shaw some encouragement.

The 21-year-old left-back has struggled to make an impression on his comeback season following a horrific double leg break.

Niggling issues have played a part in him falling down the pecking order under Mourinho, but the United manager says there is no problem with the England international.

"He has to work and wait,'' Mourinho said. "On Saturday I wanted one defender on the bench and the defender is someone who can play in more than one position.

"[Matteo] Darmian can play left-back, right-back and an emergency central defender for us so my choice was Darmian.

"The only thing I can say is that Luke is working well. He doesn't have any problem and is working well.

"He is fighting hard. There is no problem with him. He is fighting hard.''