Valtteri Bottas has big boots to fill after Nico Rosberg retirement

Over lunch with Mika Häkkinen, he was very enthusiastic about the prospects for Valtteri Bottas.

You might argue: "Having had a business interest in his fellow-Finn, Mika would say that, wouldn't he?"

Indeed he might. But Häkkinen was genuinely insistent. "Valtteri is a brilliant racing driver; a great talent," said Mika.

"He works really well with people. It doesn't mean you have to like him, but you can communicate with him and build up a relationship to do something good."

That was four years ago. Williams, in fact, got to like Valtteri as well as building up a good relationship. Whether they 'did something good' remains open to question.

With Bottas's move to Mercedes, we will get some answers as part of an intriguing new set of circumstances that poses even more questions.

Bottas's career appeared to flat-line last year. Was that due to the car? Or was it the level of settlement that unconsciously comes with a team-mate having passed his former brilliant best and no longer providing the spur a driver needs?

Throwing that thought forward, will Lewis Hamilton lose the thrilling edge we saw as he hunted down Nico Rosberg in the final four races of 2016?

And will that, in turn, reduce the competitiveness of Mercedes as a team already in mild turmoil (by their smooth standard) following the departure of both Rosberg and Paddy Lowe?

Put even more bluntly, will the comparison between Bottas and Hamilton cause critics to re-evaluate Rosberg? Of all the aforementioned uncertainty, many inside F1 believe that's the most likely scenario.

Which is perhaps one reason behind Mercedes signing Bottas for just one year, albeit it with options.

On the other hand... The step up to Mercedes could be the final incentive Bottas needs to prove Häkkinen right.

Valtteri is dedicated and quick enough to seize the moment in the manner of, say, Damon Hill suddenly having an opportunity thrust upon him at Williams and proving he was more than a solid, dependable No. 2.

And if Bottas can cause Hamilton to closely examine his new team-mate's lap traces, at least there will be none of the emotional baggage that grew from their teenage years as Lewis and Nico battled to be the first to finish their pizzas and finished with a toxic and potentially destructive partnership.

For Mercedes, having been placed between a rock and a hard place by Rosberg's surprise decision, Bottas is by far and away the best option: reliable, consistent, capable of scoring points (having failed to do so just 11 times in the last 40 starts) and with a good working knowledge of the Mercedes power unit (a big plus at this late stage).

He's also a perfect fit in the sense that the 2017 car is done and the new driver is not taller than his predecessor. In fact, Bottas wore one of Rosberg's white shirts during the presentation at Brackley.

Valtteri says his feet are smaller than Nico's. Which, if nothing else, only goes to prove Mika's boy has big boots to fill.