Limbach, who is ranked No. 1 by the International Fencing Federation, won the world championship in 2009 but finished runner-up in both the 2010 and '11 events as well as in the 2010 European Championship.
Limbach is likely to face fierce competition from second-ranked Alexey Yakimenko of Russia and reigning world champion Aldo Montano of Italy.
"There are a couple of fencers who could win a medal," Limbach said. "Only few can win gold. I am one of them."
Limbach will have a bye in the first round before taking on Hin Chung Lam of Hong Kong or Adam Skrodzki of Poland.
The German said he was feeling the pressure to do well as failing to deliver at the Olympics would make past achievements less valuable.
"If I lose in the first round," he said, "I might have been to the final of the last three world championships ... but I will be the idiot."
Limbach was trying to shut out memories of the 2008 Olympics, where he suffered an agonizing 15-14 defeat at the hands of Aliaksandr Buikevich of Belarus.
"Four years of preparation were gone in just two hours," Limbach said.
Defending champion Man Zhong of China is only regarded as an outsider to retain the title he won four years ago on home soil.
The then second-ranked Zhong became only the second Chinese fencer to win gold in the 100-year Olympic history of the sport. He added silver at the Asian Games two years later.
Montreal's Philippe Beaudry had a first-round bye and will face Dmitri Lapkes of Belarus on Sunday.