Alonso was given a drive-through, converted into a 20-second time penalty, for the way his defensive tactics against George Russell in Melbourne contributed to a last-lap crash.
Opinions over whether or not the stewards were right to punish Alonso remain divided in the paddock, although the majority of drivers are surprised that the incident triggered a sanction.
Perez believes that going as far as handing out a penalty for what happened was harsh, but he fears that the move could expose a lack of consistency within the FIA if similar incidents are ignored going forward.
Asked by Autosport for his thoughts on the incident, Perez said: "My take is it [the penalty] was definitely a bit too much over the limit. I'd say a bit unnecessary to do so.
"But my biggest fear is that we might see this incident again this weekend or next weekend and probably nothing will happen. That's my biggest fear because we've been struggling a lot to keep the consistency within the penalties.
"For example in Jeddah there was a block of [Valtteri] Bottas in Q1 at 300 km/h with two cars – [Oliver] Bearman and [Alex] Albon. No penalty.
"I block [Nico] Hulkenberg, he lost half a tenth - he goes faster on the lap after, and I get three places.
"So I think the biggest talking point should be consistency. If incidents like this are going to be penalised, they have to be penalised every single weekend. Because as a driver, it hurts a lot when you work your ass off and then you see this inconsistency."
While Perez accepts that Alonso is a driver who likes to play 'tricks' on other drivers when it comes to battling for position, he reckons that the Spaniard is someone who knows where the line is on what is and is not allowed.
"I think we all know what's acceptable, what's within the limits," added Perez. "I mean, knowing the drivers, especially like Fernando, he always does these sort of tricks, let's put it that way, always within the limits.
"I think Fernando is a very aggressive driver. But always within the limits. I've had great fights with him. He is one of the drivers I trust the most out there.
"I have to say that it was a bit too much to the limit or probably over the limit but, like I say, you know, we might see this incident again in two weeks', or three weeks' time, and nothing will happen."
Perez was not the only driver expressing surprise at the way in which the stewards dealt with the Alonso incident.
McLaren driver Lando Norris said on Thursday that while Alonso's behaviour was 'odd', it was not enough to be deemed a brake test that was worthy of sanction.
"What Fernando did was odd, like, extreme, but I don't think it's even close to being regarded as a brake test," he said.
"Should it be a penalty in any way? No. George, in my opinion, should have seen it coming. I don't want to comment too much on it, but George had time to see what was going on."
He added: "If George was a lot closer, and then suddenly in the middle of a straight Fernando lifts off, and George has to suddenly swerve or whatever, then I guess it's a bit more of a question.
"But George didn't have to do anything but brake five metres earlier. And there would have been a different outcome.
"That's also down to George. When you're a driver, you have to react to everything around you and it's worse going into Turn 1 at the start of a race. You have no idea when people are going to brake, but you have to react."
