Here's why Lawson recieved a quick demotion from Red Bull

Regarding Lawson's initial promotion, Horner said, “I think, as I said previously to Craig, that with hindsight, I think we just asked too much too soon from Liam.”

He continued, “We've got a lot of work to do with the car, and unfortunately, I think that you know it's sometimes you've got to be cruel to be kind, but he's not out of Formula One. He's gone back to the Racing Bulls. We still believe in him as a talent for the future, and making use of Yuki's experience will hopefully enable the engineers to make faster progress with the car.” 

On the topic of Tsunoda, Horner was full of positive words for the Japanese driver after the first session. “He brings experience, and that knowledge is very useful as this season's all gonna be about a development race."

He said, “That's why we took the decision early. I think Liam would have got there, but it might have taken you know five six seven races or half a season; we don't have that amount of time.”

Both Lawson and Tsunoda said that while there were rumours, they did not receive the news until after the Chinese Grand Prix weekend was over.

About the decision to swap them, he said, “After discussing it internally, we decided ‘we've got to rip the plaster off this now and get on with it’.”