Carlos Sainz has lost his personal trainer to Max Verstappen after eight years of working together.
The Ferrari driver has worked with Rupert Manwaring since making his F1 debut in 2015, when he drove for Toro Rosso alongside Verstappen.
While Verstappen was quickly promoted to Red Bull and has won three world titles, Sainz joined Renault, McLaren and now Ferrari but maintained his partnership with Manwaring.
However, Verstappen has poached Manwaring after his own personal trainer Bradley Scanes opted for pastures new, with the intention of spending more time at home.
Verstappen’s father, Jos, worked with Manwaring’s father during his own F1 career.
Manwaring works for the Hintsa Performance company, launched by Dr Aki Hintsa – who worked with Lewis Hamilton and Mika Hakkinen before he passed away in 2016.
Sainz, meanwhile, was a frustrated figure by the end of the season-finale in Abu Dhabi on Sunday.
The Spaniard endured a fortnight to forget, demoted 10 places in Las Vegas after his car was damaged due to a loose manhole cover, before qualifying only 16th on the grid for the final race of the season.
"Today, the last two weekends, this last weekend in general, haven’t gone like I expected or like we wanted to finish the year," he said.
"Honestly, [I’m] very disappointed and obviously not happy.
"Given how close it was in the end with the constructors’ championship, we will have to sit down and analyse what we could have done better today and what was going on.
“Clearly the pace this weekend and the overall feeling with the car and everything, the end wasn’t good."