Compounding their misery, Red Bull endured a disastrous Monaco Grand Prix, with Sergio Perez crashing out on the opening lap and Max Verstappen only managing sixth in the race.
Red Bull’s rivals have been closing in on them gradually this season, culminating in a stunning victory for Lando Norris at the Miami Grand Prix.
“Red Bull have genuinely lost in Monaco,” Collins said.
“Red Bull don't seem that confident going forward and that's really exciting for us watching at home.
“Part of that parcel is the fact that Ferrari have two guys regularly very close together on track and regularly taking good points.
“Those types of things will stand them in stead for the rest of the year and that's where Red Bull really need to start questioning things a little bit.”
“If McLaren and Red Bull continue to improve or if McLaren and Ferrari continue to improve then Red Bull are in trouble.”