When Lewis Hamilton pulls down his visor for Sunday’s Bahrain Grand Prix, he will know that it could be the beginning of the end.

During the off-season, and following months of negotiations, Hamilton signed just a one-year contract extension with Mercedes.

From both sides, there was little razzmatazz to welcome a deal which was announced just a month before the new season.

Hamilton, who we know is hardly hesitant to use social media, did not devote a single world about it to his 22 million Instagram followers.

After the Briton surpassed Michael Schumacher’s win record at last October’s German Grand Prix, he said he wanted to continue racing until he was grey. So, why the apparent change of heart?

One school of thought is that the 36-year-old requested a shorter deal to keep his options open.

His interests in fashion and music are well documented, while there is a major overhaul in the regulations next year. Both points hold some credibility. Indeed, who is to say Mercedes’ remarkable dominance will continue?

But can Hamilton ever replace the highs of winning motor races – something he has been doing for as long as he can remember –  by playing an Adele cover on the piano, or designing another clothing range for Tommy Hilfiger? It is unlikely.

We must also remember that no driver in Formula One is indispensable. Michael Schumacher was 37 when Ferrari told him his services were no longer required.

Team principal Toto Wolff insists Mercedes’ priority is to speak with Hamilton before they – as he put it – “flirt” with drivers outside of their current line-up – Red Bull’s Max Verstappen and Williams’ George Russell (both 23) are on his radar for 2022.

But tellingly he stopped short of saying the ball is entirely in Hamilton’s court when it comes to his Mercedes future.

Mercedes would be foolish not to consider life after their superstar and from their perspective, what better way to sign off a record-breaking partnership by carrying Hamilton to an unprecedented eighth world title in a machine painted black to highlight the fight against racism?

And the script following last year’s one-sided campaign, which saw Mercedes win 13 of 17 races – with Hamilton victorious on 11 occasions – suggested that another title would be a formality.

Yet the evidence of the sole three days of testing in Bahrain earlier this month, indicates the aforementioned script never got commissioned.

Mercedes ran into mechanical trouble, while the car appeared a handful, too. Hamilton spun not once but twice. Both unheard of. The world champions have had a fortnight to rectify the problems.

For Red Bull, there were no such worries. Verstappen posted the fastest time of the test with the new Red Bull speedy and reliable. Suddenly, Hamilton and Mercedes might have a challenger on their hands.

The prospect of Hamilton and Verstappen – the latter desperate to dethrone the king – battling for this year’s championship is a salivating plotline and one the sport has been crying out for.

The makers of Netflix’s successful Drive to Survive series and the sport’s new boss, Stefano Domenicali will be licking their lips.

It would be prudent to cast off Mercedes as has-beens, and on the eve of the new campaign, Verstappen, quite rightly, said the Silver Arrows must still be considered top dogs.

“Mercedes are the favourites,” he said. “How can they not be when they have won seven world championships in a row?

“I’m sure Mercedes also want people to think we are the favourites and put the pressure on us.”

There have been false dawns before. In 2019, Sebastian Vettel and Ferrari were expected to blow Hamilton and Mercedes out of the park. Needless to say, it did not happen.

Vettel has subsequently been transferred to Aston Martin, while the famous Prancing Horse are staggering into this season following their worst campaign in 40 years.

But all sporting dynasties must come to an end and could this finally be the year where Hamilton and his Mercedes team are knocked off their F1 perch?

Sunday’s race under the 495 bulbs that light up the Bahrain International Circuit here in Manama will go some way to providing us with an answer.