Lewis Hamilton has been warned his time at the top of F1 could soon be up despite his strong finish to the 2021 season.
Hamilton, 37, appeared out of the title race when he trailed Max Verstappen by 19 points with four races to go, but then was at his mercurial best to notch wins in Brazil, Qatar, and Saudi Arabia.
It meant the Mercedes man went into the final race in Abu Dhabi level on points with his title rival, and he seemed certain to take the chequered flag at the Yas Marina as well before the controversial late safety car procedure that ultimately gifted Verstappen victory.
Having been 'disillusioned' at what transpired, the British icon then reportedly contemplated retirement from the sport, before confirming this month he would be racing for the Silver Arrows in 2022 alongside compatriot George Russell.
Hamilton has cited his desire to make history as one of the reasons for him continuing, as he targets an unprecedented eighth world title win.
However, Red Bull advisor Helmut Marko believes he will struggle to compete with Verstappen, 24, for much longer.
"Hamilton delivered an incredible second half of the season," he told Austrian news outlet, OE24.
"I can hardly imagine he can drive at this level for much longer. He's at his zenith now, age is slowly coming into play."
Marko, who also serves as head of Red Bull's driver development program, also tipped the Dutch driver to get better from here.
"He's World Champion now and he will get stronger," he added.
Despite Marko's prediction, there seemed little sign of Hamilton slowing up during three days of pre-season testing in Barcelona this week, as he notched the fastest lap in Spain with Mercedes the quickest team on show.
All F1 teams will head to Bahrain for three more days of testing from March 10-12, before the country hosts the opening race of what will be a record-breaking 23 event season on Sunday, March 20.
It promises to be an intriguing season and not just because of Hamilton's revenge mission on Verstappen, with brand new technical regulations coming into the sport.
The restrictions are designed to make racing more competitive, and threaten to end the dominance the two leading drivers enjoyed last year, where they won 18 of the 22 Grands Prix between them.
