Perez failed to score points for the third time in five races after he finished 17th at the British Grand Prix on Sunday.
The Mexican beached his car in qualifying at Silverstone and started from the pit lane, but a strategy gamble to go onto intermediates early during the race did not pay off.
Speculation around Perez’s future at Red Bull ramped up across the Silverstone weekend amid suggestions that the next two races which take F1 into its summer break, Hungary and Belgium, could be pivotal for the 34-year-old to find a way out of his slump in form.
“It’s a massive issue. This was just a terrible weekend. He was unlucky in some ways as well. This won’t happen every weekend,” Button told Sky Sports F1 at the end of the British GP.
“They are on the backfoot. Perez needs to be scoring some points at least, even if he’s not finishing right behind Max.”
Perez has just 15 points to his name from the last six events, while Verstappen has racked up 119, including three wins.
Button understands the pressure of driving for a top team but says changes will be made if Perez doesn’t improve.
“They can’t let it go on forever. If at the next race he doesn’t score points again, soon enough, they will have to get him out of the car and put someone else in,” he continued.
“It’s not a nice feeling for a driver. It’s tough. For a driver it’s horrible but for them the constructors’ is important.”
