Red Bull's Helmut Marko says he has "no idea" what happened to Daniil Kvyat and why the Russian driver lost his natural speed, resulting in him being dropped by the Red Bull brand altogether.
Kvyat was promoted from Toro Rosso to Red Bull in 2015 where he outscored Daniel Ricciardo in his debut season with the team, but the following year he was demoted back to the junior outfit as a result of several first-lap incidents, with Max Verstappen taking up his Red Bull seat.
Kvyat continued to struggle and ahead of the Malaysian Grand Prix he was dropped from Toro Rosso, only making a one-off return in Austin to stand-in for Pierre Gasly, who had other commitments. Following that race, Kvyat was dumped by the Red Bull driver programme.
Marko believes the problems experienced by Kvyat were psychological but has no explanation as to why it happened or why they couldn't be overcome.
"Unfortunately he just showed it [natural speed] in his first year with Toro Rosso and in his first year with Red Bull Racing. After that his performance drastically went down.
"In short, something happened to him mentally. He lost his speed. We don't know [why]," explained the Austrian. "We tried many things, but his speed just wouldn't come back. Unfortunately we have no idea what happened.
"There were also too many accidents at the start of a race, and he didn't react too well to it either. He retreated into his shell and didn't want anybody to tell him what to do."
Kvyat's former boss Franz Tost believes a short break from racing will serve him well and rejuvinate the 23-year-old, allowing him to make a comeback.
"I hope for him that he gets another chance, as I think he deserves to be in F1. Maybe a short break – to get organised again – and probably we will see Daniil back at his usual performance level with another team."
