As the final whistle blew at The Hawthorns, Zlatan Ibrahimovic found himself standing in the centre circle with the ball in his hands. Ultimately, he was one goal shy of being allowed to keep it but given how central the player had been to the outcome of proceedings, it was an apt sight on a dark December evening.

The Swede’s double secured a deserved fourth successive victory for Manchester United. It also extended his tally to 16 goals in 25 appearances and 10 in his past nine. An excellent return made more notable by that fact that by still being on the pitch when the referee, Anthony Taylor, called time, Ibrahimovic had maintained his run of completing every Premier League match for which he has been available since joining United. Sixteen starts, 16 finishes, 1,440-plus minutes played.

That is not what many predicted when Ibrahimovic arrived on these shores in July amid a blaze of hype. United’s social media team did not hold back with the #ZlatanTime hashtag and turned the whole thing up to 11 by including one in a tweet extolling how the striker had “broken #mufc power records in tests during his medical”. Yet the sense from outside was that Ibrahimovic, while undeniably talented, was too old for the challenge ahead. A free transfer but the wrong signing for United.

Close to the halfway stage of the season, however, and the 35-year-old is going strong. José Mourinho has described him as “phenomenal ” and from the player himself has come, in his own inimitable style, the insistence that he has even more to offer. “The older I get, the better I get, like red wine,” he said. “You like red wine? I am a perfect example of that. I’m settling in and I feel happy, I feel good. Even if I’m 35, in my mind I’m 20. I think I could play at 50.”

It is safe to say that if Ibrahimovic is still kicking a ball around in 2031 it will not be for United, but for the time being there is no doubting his value to the side. The former Paris Saint‑Germain striker has brought experience, muscle, craft and ruthlessness to the point of their attack, which was there to see in the goals he secured in the 2-0 win at West Bromwich Albion. Ibrahimovic’s first came via a precise header after he beat Gareth McAuley to Jesse Lingard’s excellent cross, having craftily pulled back the Albion defender. His second took a deflection off Craig Dawson but only after United’s No9 had manoeuvred between McAuley and Matt Phillips with verve.

“He’s good in the air, he’s got great feet, he’s powerful. Look at his second goal – most players are looking to pass but he chips it over the defender and just wellies it,” said Ben Foster, the West Bromwich goalkeeper. “How old is he? 35? Jesus – he’s brilliant. You don’t do what he’s done by just being a big lump.”

Zlatan Ibrahimovic, centre, fires his second goal at The Hawthorns, which came about after he had burst past Gareth McAuley and Matt Phillips. Photograph: Michael Steele/Getty Images

Of that there is no doubt and a trait that is somewhat overshadowed by Ibrahimovic’s occasionally comical self-regard is his dedication to optimum fitness. This is a man who puts in the hours behind the scenes - including practicing Taekwondo, in which he holds a blackbelt – and what persuaded Mourinho, having worked with him at Internazionale, that the veteran could cut it in England. “The only thing that surprises me [about the Premier League] is that the game is not controlled,” Ibrahimovicsaid. “Back and front, back and front, the rhythm is high but this is how the game is and you have to adapt your body to it. I have played in different championships in different countries and always adapted.”

As well as being a source of goals, Ibrahimovic is also an outlet for others. On Saturday he assisted two scoring attempts, the joint highest in the visitors’ ranks alongside Lingard, and generally allowed United to build momentum with his hold-up play.

This was also a contest, however, in which the player showed his devilish side with a collision with Dawson for which he could have been sent off – he was shown only a yellow card by Taylor – and therein lies a concern for United: what if Ibrahimovic is missing, either through suspension or injury? That was the case for one league game this season, the 1-1 draw with Arsenal when United created the bulk of chances but were undone late on. What might have been if their suspended striker had been out there?

As things stand, the Swede has contributed more than three times as many league goals as United’s second‑highest scorers – Paul Pogba, Juan Mata and Marcus Rashford. They and others need to wade in with more, especially as Ibrahimovic is likely to go through a slump and/or require a rest. As Mourinho said: “He cannot play 60 matches”.

For the time being, however, he is fit and firing and it caught the attention on Saturday when the travelling supporters began to sing Eric Cantona’s name shortly after it became 2-0. A little under 20 years on from the Frenchman’s retirement, United have another forward imbued with a potent mix of charisma and talent.