The 23-year-old, who took over from Lewis Hamilton after the 2008 Formula One world champion left for Mercedes at the end of last season, assured reporters at the Bahrain Grand Prix that he could handle it, however.
"I have definitely felt the pressure. At McLaren everyone is watching your performance – in every single practice session, every single race," he said.
"I find it quite amazing that…after one bad weekend I received so many criticisms.
"If I am totally honest, I am not bothered about it. I am here to do my job and I will try my best this weekend and the next 16 weekends."
Perez has scored points in only one of his three races for McLaren so far, a ninth place in Malaysia, but much of that is down to the car which has been far less competitive than the team had hoped.
Teammate Jenson Button, the 2009 champion, was fifth at the last race in China and ninth in the Australian season-opener. But he is in his fourth season with the team and is the most experienced driver on the starting grid.
In Shanghai, Perez tangled with Lotus's Kimi Raikkonen and was criticized by some rivals for weaving on the track when they tried to overtake.
After China, team principal Martin Whitmarsh supported the driver and told reporters that he had asked the Mexican to 'use his elbows' and be tougher on the track.
"We had a word about it, and it's difficult to judge when you can be aggressive and when not," said Perez, when asked about the comments.
"When you are on a different strategy and mainly looking after the tires, the worst thing you can do is fight someone next to you who is on a different strategy, who is two or three seconds faster than you.
"So you are not fighting that guy, you are fighting someone who is behind you. It is a difficult balance to judge." GMA News Online/Reuters