Gasly arrived at Red Bull following the departure of Daniel Ricciardo to Renault but he struggled for form and was replaced by Alex Albon. After returning to Toro Rosso, Gasly enjoyed a far better spell including a dramatic podium at the Brazilian Grand Prix as the constructor finished sixth in the Drivers' Championship.
In an interview with the F1 website, Gasly refused to go into detail as to what was behind his pick up in form.
“To be fair there are many reasons why and I don’t really want to go into details," Gasly said.
“I’ve just reviewed the whole season last year, the things I could do better on my side and the positive things.
“There are things that will stay private, they will always stay private, so I just focus on what I could change on my approach and be even better than I was at the end of the year with Toro Rosso, try to take myself to another level and be more competitive.
“But after that January 1 a new chapter started with AlphaTauri and I’m just super excited to get the season started.”