Does Wehrlein have the right stuff for Toro Rosso?

Although several names have been linked to the seat, including Lando Norris (McLaren) and Antonio Giovinazzi (Sauber) who have confirmed drives for 2019, Pascal Wehrlein has emerged as the front-runner.

As it stands, Pierre Gasly departs Toro Rosso for Red Bull and 'prodigal son' Daniil Kvyat return for another crack at the top flight leaving one seat, currently filled by Brendon Hartley.

And that's where it gets complicated.

Hartley has not delivered at the highest level, relative to Gasly he has been mostly outperformed, the New Zealander struggling to make the transition from WEC, where he was double world champion, to the top flight.

Helmut Marko, who fired him years ago then rehired him, has been patient with the 28-year-old, but at the same time has made it quite clear that there are several drivers being considered for the drive. But it is not a certainty that Hartley will be dropped.

In qualifying for the Japanese Grand Prix, Honda territory, Hartley qualified sixth with Gasly behind him, prompting team chief Franz Tost to comment, "It was a fantastic achievement. [Brendon] was quick from the first moment he got here."

"I think for him the most important thing is that he now understands how to use the tyres a lot better. Brendon does a good job, why should we change him?" added the team chief.

But a day later the #28 got off the start line badly and Hartley spent the afternoon in no man's land and out of the points. At the end of the race, in which he started ahead of Gasly, the New Zealander finished 22 seconds behind the Frenchman. A stark reminder to his bosses why he may not be the real deal for F1.

Word is that, after the Russian Grand Prix weekend, Marko gave Hartley the ultimatum of beating Gasly in all remaining races - he faltered at the first hurdle at Suzuka.

No surprise that there is a queue of drivers knocking on the door to replace Hartley should his bosses decide to axe the likeable 28-year-old at the end of this season, Marko suggesting at one point that ten drivers were on his list

Most recently Wehrlein was added to this list, apparently joining the likes of Robert Kubica and Esteban Ocon as possible candidates. Other outsiders linked with the seat include Mick Schumacher (denied by Red Bull) and most recently Alexander Albon.

Of all the candidates, Wehrlein has made a good case for himself by extricating himself from the Mercedes driver programme and turning a down a three-year deal to lead Mercedes' Formula E campaign.

Major decisions by him that clearly show his intent to cut it in Formula 1 at all costs.

And hence a Toro Rosso stint might not be far-fetched, after the German ended his contract with Mercedes Marko acknowledged, "It's a different story now, yes. We have not decided yet, but Wehrlein is on a long list."

Swiss Ex-F1 driver turned pundit Marc Surer said on a recent Starting Grid podcast episode, " We have seen that Hartley has not delivered, even though there was the Suzuka qualifying highlight, but what followed was a below-par race."

"I would say that Pascal would be worth a try. He still deserves another chance and, I think, with Toro Rosso led by Franz Tost it would be a different story, he can show what he has and what we have seen from him in the past."

The German's career to Formula 1 was unconventional in that he shone first in the tin-top DTM series, where he became the youngest champion in 2015, before Mercedes backed him into a Manor seat in 2016.

Wehrlein's rookie season was solid, although he his Manor teammate (for the final nine races of 2016) but Mercedes colleague Esteban Ocon when it came to a shootout between the two for the Force India seat, the Frenchman got the nod.

Mercedes brokered a deal and Wehrlein was a Sauber driver for 2017. His stint with the Swiss outfit got off to a bad start as he had to miss the first two races after he crashed during the Race of Champions event in December. He injured his neck, far more seriously than he let on.

He returned for his Sauber debut at the Bahrain Grand Prix.

Fast-forwarding to the Abu Dhabi finale and summing up his season "underwhelming" springs to mind, despite scoring all five points Sauber managed that year, teammate Marcus Ericsson was pointless.

Indeed, Wehrlein was better than journeyman Ericsson but not in the way rookie Charles Leclerc has trounced the Swede this year.

During that season, dovetailing between his Sauber duties, Wherlien also spent time testing the pace-setting Mercedes where his performances were impressive relative to the formidable talents of Lewis Hamilton and Nico Rosberg.

At one point Wehrlein was in line to replace Rosberg when he quit Mercedes at the end of 2016, but word is team chief Toto Wolff wanted to avoid another volatile scenario within the team, which would likely have been the case with Hamilton-Wehrlein, and instead opted for Valtteri Bottas.

With too many bums for seats on the grid this year, Wehrlein went back to DTM, but always kept an eye on a comeback to the top flight.

Surer, who had close access to Wehrlein within the Swiss team, recalled, "At Sauber, I noticed he was really fast in a good car, as soon as he had a car with quirks he struggled."

"After clean running with Mercedes in testing, he was unsettled very quickly with the not-so-clean Sauber. As soon as the rear was unstable he would brake too early," added Surer who would have been privy to the team's telemetry.

"These are things that you can iron out of him, a Franz Tost will have a good talk to him and he will learn how to deal with these things. With Toro Rosso, he would have better leadership and guidance than he has had in the past."

What impresses Surer most about Wehrlein is, "Pascal feels no pressure, he can handle that and deal with difficult situations very well."

In a nutshell, Hartley has a lifeline of sorts but massive results are required from him in all the next four races and still, there would be questions asked.

Meanwhile, until Marko and the Red Bull gang make that call, Wehrlein at 23 is worth considering for Toro Rosso because it is fair to say the German has unfinished business in Formula 1 and time on his side.