Norbert Haug has slammed Haas for further destabilising its relationship with Mick Schumacher by giving Antonio Giovinazzi Friday practice outings at forthcoming grands prix.
Haas boss Gunther Steiner confirmed that it had been Ferrari's request for F1 reserve and 2022 Formula E driver Giovinazzi to return to an F1 car at Monza and Austin.
Amid parallel rumours of talks between Steiner and likely McLaren refugee Daniel Ricciardo, former Mercedes boss Haug slammed the move.
"Every kilometre that a driver does not get hurts him for the race weekend," he told Sky Deutschland.
"I don't know if there is a contractual agreement with Ferrari, but a team like Haas should be concentrating on its own drivers."
Steiner has put even more pressure on Schumacher's shoulders by stating categorically that the 23-year-old should "score more points" if he wants to keep his race seat for 2023.
Haug hit back: "If I say on one hand that I expect more points, then a driver must also be able to say that I expect more practice."
The 69-year-old German said his young countryman deserves better support from Haas.
"If you support a driver and give him the opportunity, then something will progress," said Haug. "A driver is a race horse, not a plow horse. You have to give him courage."
