Carlos Sainz admitted it was very "disappointing" to end his final race for Toro Rosso on the opening lap after sliding into the gravel through the Esses in Sunday's Japanese Grand Prix.

The Spaniard, along with the man he'll replace at Renault from Austin, Jolyon Palmer, looked to make their way through from the back of the grid at Suzuka after both taking engine penalties, but while the Briton finished 12th, it was a short-lived experience for Sainz with his third first lap retirement of the year.

“How disappointing, this wasn’t the way I wanted to end my time with Toro Rosso, that’s for sure,” he said once back in the paddock.

“I’d like to say sorry to the whole team for retiring on the first lap. I was trying to risk everything at the start to try and gain some positions, so I went around the outside at Turn 6 and I found a lot more dust on the track than I was expecting, and lost it; as simple as that.

“It’s a shame, because I was really looking forward to finishing on a high here in Suzuka with the team.”

Reflecting on his time with the junior Red Bull team, which he has been with since the start of 2015, he added:  “I’m going to remain positive: these three years here have been absolutely amazing – it’s been an ideal preparation for me.

“The driver I am today, compared to the driver I was in 2015, is a more complete and better one, and this is thanks to Toro Rosso, who are a great group of professionals.”

It was an unexpected announcement on Saturday that Sainz, who was already set for Renault in 2018 regardless, would be making the switch four races early, particularly after Palmer had reportedly refused a financial offer to leave the team after the Singapore Grand Prix.

The 22-year-old was also caught off guard by the timing but is pleased to have an elongated opportunity to settle with the Enstone team.

“I actually knew about half an hour before the announcement so it was quite unexpected from my side,” Sainz revealed. “A big surprise like for you guys! My manager let me know that Cyril [Abiteboul] had told him.

“When I went to bed I was happy because I knew it was a good chance for me to adapt to the car a bit earlier than we expected, to get to know my engineers, the team, the mechanics a bit earlier.

“I liked it, although I was not very emotional or happy because I was so focused on the weekend that it was difficult to take the mind out of that.”