The pair lost the second of their three permitted engines for the season as a result of irreparable damage picked up in separate incidents at the British and Hungarian grands prix.
Verstappen’s power unit was damaged in his massive 51G shunt following a controversial first-lap collision with title rival Lewis Hamilton at Silverstone, while Perez’s car took a big hit in the Turn 1 carnage triggered by the other Mercedes of Valtteri Bottas in Hungary.
A Honda spokesperson confirmed to Crash.net on Thursday ahead of this weekend’s Belgian Grand Prix that both engines were written off in the respective accidents.
“That is hugely frustrating for Honda as it’s not due to reliability; it’s due to accidents that we haven’t caused so they are feeling the brunt of this as we are on the chassis-side and it’s not to be underestimated on the cost cap side,” Horner said.
“It does need to be looked at because in a cost cap environment, it’s brutal the incidents we’ve had in the last couple of weeks.”
Honda and Red Bull are yet to make a call on when Verstappen and Perez will move onto their fourth power units, a switch that will automatically result in a grid drop.
Spa-Francorchamps and Monza are two venues teams have traditionally chosen to make tactical engine changes at in an attempt to limit the hit of a grid penalty due to the overtaking opportunities at both circuits.