Mass anti-government rallies that began during last June are expected to continue during the World Cup, to be held in 12 Brazilian cities from July 12 to July 13, reported Xinhua.
Pele called on Brazilians to temporarily put aside their disquiet over bad governance and corruption.
"As a Brazilian, it makes me sad," Pele told the media.
"We have two great chances to show off our country to the world with the World Cup and (Rio 2016) Olympics. It's an opportunity for the country to make money, develop tourism and it's important the protests don't ruin all of this. We are working as hard as we can."
The 73-year-old rates Brazil among the tournament favourites but warned the path to a sixth World Cup will be littered with obstacles.
"We are used to seeing Brazil score many goals but the World Cup is very different," Pele said.
"It's a short tournament. We have to be ready because there are some great teams like Germany and Spain, who have had the same group of players for eight years."