Mercedes team chief Toto Wolff feels that Lewis Hamilton would have not won a fifth Drivers' Championship at the end of the 2018 season without the support of Valtteri Bottas.

Brit Hamilton concluded a stellar year in the franchise by earning another championship-winning trophy, beating German rival Sebastian Vettel to the top prize.

However, Finnish driver Bottas, who became only the third Formula One competitor to go an entire calendar season without winning a race in a championship-winning car, is still receiving credit from the higher ups.

Bottas' season went downhill following his promising start at the Chinese and Azerbaijan Grand Prix events on the circuit, with a puncture and a safety car meaning those races didn't go his way.

From a winning position at the Russian Grand Prix, Bottas was instructed by Mercedes' team bosses to allow Hamilton in front of him, as he battled Vettel for another coveted Drivers' Championship.

But despite a poor personal season on the track for Bottas, Wolff has praised the Finn for his team work for the greater cause, which helped win silverware. 

And Mercedes team principle Wolff admitted that both the Drivers' Championship or Constructors' Championship titles wouldn't have been won without the 29-year-old.

"We wouldn't have won the Drivers' Championship and the Constructors' Championship without Valtteri," he said, as per GP Fans.

"Valtteri, even with his bad luck, did never allow the spirit and the mindset to drop within the organisation. He was always capable to maintain the high spirits.

"You see drivers when they lose the ability to win the championship the whole thing goes really down the drain. It becomes negative, it becomes dysfunctional. Valtteri until the very end kept us in a positive place."

Meanwhile, Wolff praised Hamilton by saying: “I think he performed at a higher level in the first half of the season, and that is reflected in the points.

“He would have been leading the championship after Baku, but the moment you take away the ability to win the world championship for a driver who is so focused on becoming a world champion if he in a Mercedes, that has a negative impact."