Helmut Marko believes Daniel Ricciardo’s 2018 departure from Red Bull was the “turning point” of his F1 career.

On Thursday RB confirmed that Ricciardo has been dropped from their line-up, with Liam Lawson coming in to replace him for the final six races of the season in a move which likely signals the end of the 35-year-old Australian’s F1 career.

An eight-time grand prix winner, Ricciardo was at one point considered to be one of the leading drivers on the F1 grid, but his recent performances at RB have underwhelmed, following on from his McLaren struggles in 2022.

Red Bull motorsport advisor Marko reckons Ricciardo’s career started to decline after he quit the team at the end of 2018 in order to take a lucrative offer from Renault, before later switching to McLaren.

”I think the decision to leave Red Bull Racing was the turning point in his career,” Marko told Motorsport-Total.com.

“Then he didn’t have a winning car at either Renault or McLaren. He did win at Monza, but those were special circumstances.

“I don’t know what exactly happened, because if we knew, we would have helped him.

“But the speed and, above all, this late braking, and then he goes left or right… in these last few years he tried but it was no longer there, the killer instinct was gone.”

On Ricciardo’s decision to leave Red Bull, Marko added: “He had certain reservations about the Honda engine and apparently he listened more to the sweet talk of Renault and Cyril Abiteboul.

“Financially, there wasn’t much difference between what Renault offered him and what we offered. I also told him: ‘Shoeys will be hard for you’. I don’t think we’ve seen Renault on the podium a lot.

“He came to us, beating Vettel with three-to-zero victories in 2014 and after that, Daniil Kvyat was faster than him at times, but over the season he also had him under control.

“And then Max came and he got stronger and stronger, so that was certainly one of the reasons for his decision to choose Renault over us.”

Ricciardo’s final hurrah at the Singapore Grand Prix was to help former Red Bull teammate Max Verstappen’s title bid by securing the fastest lap and denying his main rival Lando Norris an extra point.

Marko said Red Bull had informed Ricciardo of their plan and felt his fastest lap was a fitting farewell.

“[The timing] was related to a variety of factors and obligations,” Marko explained. “He was informed, and the worthy farewell performance was, I think, the fastest lap.

“That still showed what potential he has, not continuously and not at the level that would have justified him coming to Red Bull Racing, but that was an impeccable performance.

“I think it was clearly communicated that he has to be significantly better than Yuki Tsunoda and he only managed that in a few races, so it was clear that this story of the prodigal son rejoining Red Bull Racing unfortunately didn’t work out.

“He said very well that he is at peace with himself, and he has come to terms with the situation and we will see what his plans for the future are.”