Formula One: Abu Dhabi to be Kiwi Brendon Hartley's final Grand Prix - Mark Gallagher

Kiwi Brendon Hartley's tenure at Toro Rosso is almost certainly to end after next weekend's Abu Dhabi Grand Prix.

That's the opinion of respected motorsport commentator and former member of the Jordan F1 team Mark Gallagher.

The 29-year-old is 19th of 20 drivers having scored four points through 20 races while his young teammate, Frenchman Pierre Gasly has 29-points.

Speaking to RadioLIVE's Sunday Sport, Gallagher said F1 is a results business - and despite his fair share of bad luck, Hartley hasn't quite got the job done in 2018.

"He has been outscored by his teammate Pierre Gasly quite comprehensively," Gallagher told Andrew Gourdie and Jim Kayes.

"Four points for Brendon plays 29 for Pierre, who has been promoted to the senior team next year and that is quite a huge differential in performance.

"Brendon has had some bad luck and some reliability issues but he has also had a few poor performances and everything is kind of stacked against him right now."

Formula One: Abu Dhabi to be Kiwi Brendon Hartley's final Grand Prix - Mark Gallagher

Gallagher has heard whispers that the Kiwis fate is already sealed, believing November 25 at the Yas Marina circuit will be his final Grand Prix for the Toro Rosso team.

Gallagher said he wouldn't be surprised if Hartley has already been told he is surplus to requirements for 2019.

"I think unfortunately it will be his last race in Formula One for the foreseeable future," Gallagher assessed.

"I say that from picking up on a few things from talks with people connected in the paddock following the way this season has developed for him.

"I think it is really important to say Brendon deserved this opportunity to drive in Formula One and he has tried so hard to make the most of it.

"The facts of how the season has gone really stack against him, and that is why there is this feeling that he won't be part of the Toro Rosso team next year.

"That is just a feeling - no one has confirmed this, but I am sure he knows his fate and I believe both him and the Red Bull management already know the answer.

"It's only small margins so it will be a tough moment for him if he is not on the grid next season."

The 56-year-old British pundit does see a faint opportunity for Hartley to return to the F1 paddock in the future.

Given his pedigree as one of the world's best endurance drivers, Gallagher said there is no doubting the Palmerston North native is as talented as any driver outside the top six.

In fact, the man Hartley replaced at the end of 2017 is proof that Red Bull Racing might not give up despite his impending dumping.

Russian Daniel Kvyat will return to the grid next year, filling the void that Gasly leaves as he takes his place alongside Max Verstappen in the senior team.

Kvyat has numerous incidents throughout his time with the Red Bull and Toro Rosso teams and was eventually let go ahead of the United States Grand Prix last year.

But the 24-year-old has won his seat back after impressing as a test driver for Ferrari this season.

"Red Bull are not quite as brutal as others, and are very good at building long-term relationships with the people that drive for them," Gallagher noted.

"They believe in giving drivers a second, sometimes third chance in Kvyat's case. They believe he has really matured as a driver and he has undeniable talent.

"Brendon is a World Endurance champion and a former Le Mans winner - it's not like he lost his talent overnight.

"He is still extremely talented but it's that white-hot heat atmosphere of Formula One that has led to a disappointing year for him."

Hartley's options of the F1 grid are limited for 2019 with only Williams, the former Force India and Torro Rosso to confirm their final driver for the season.