Carlos Sainz says he wasn't expecting to move to Renault before the end of the season and was made aware of the decision just 30 minutes before it was confirmed.
Renault announced late on Saturday that Carlos Sainz would race for the French outfit at the US Grand Prix in Austin, replacing Jolyon Palmer alongside Nico Hulkenberg.
There had been speculation of a premature move in Singapore, after the manufacturer announced Sainz's recruitment for 2018, but with Palmer insisting that his contract would guarantee his presence at Renault until the end of 2017, the rumors were discarded.
"I actually knew about half an hour before the announcement so it was quite unexpected from my side," Sainz said.
"A big surprise like for you guys! My manager let me know that Cyril [Abiteboul] had told him."
Sainz admitted that the news didn't hit him immediately as he was entirely immersed in his race weekend with Toro Rosso. But on Saturday night, it progressively sunk in.
"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."