After Max Verstappen’s early exit from the Belgian Grand Prix, in what was his fourth mechanical retirement of the year, Jos Verstappen told Dutch TV channel Ziggo Sport that the situation was ‘very difficult to accept’.  
But Jos, himself a former F1 driver, stopped short of suggesting that he and his son had completely lost faith in the team and were looking elsewhere for Max’s F1 future.  
"I notice about Max that he's very disappointed,” Jos said. “It's tough to keep yourself motivated the whole time when things are going like this.
"I mean, he's doing very well in qualifying, he's half a second quicker than his team-mate and he's just behind the Ferraris.
"And then, after seven or eight laps, he's standing at the side of the track again. This should not be able to happen, certainly not at a top team."
Jos also rejected speculation that Max was harder on his equipment than team-mate Daniel Ricciardo, and that this might explain the spate of unreliability.
"People are asking that question again if Max is being too tough on his equipment. But that's complete nonsense.
"He can't overdrive, he can't break the material. We all know what it is: it's just the equipment that isn't good enough.
"I think we all need to calm down for a bit and then maybe we need to sit down with each other because this won't last if things keep going like this."