Brazil's assistant coach Cesar Sampaio on Sunday asked the footballing world to send its prayers to Pele as the icon receives treatment in hospital for a respiratory infection.
The 82-year-old Pele, widely regarded as the greatest footballer of all time, was hospitalised last week and has been having treatment for colon cancer.
"Regardless of your religion, we ask you to say a prayer or do whatever you do to send him your good vibes," Sampaio told reporters at the World Cup on the eve of Brazil's last-16 clash with South Korea.
Head coach Tite also spoke about the esteem with which Pele is held in his homeland.
"He is possibly the only person with whom I was shaking when I met him," said Tite.
"I was shaking, my hands were sweating, my heart skipped a beat and I thought, 'Wow, I'm going to meet Pele!'"
Pele said on Saturday that he felt "strong, with a lot of hope".
"My friends, I want to keep everyone calm and positive," Pele said in an Instagram post. "I'm strong, with a lot of hope and I follow my treatment as usual."
Media reports earlier on Saturday said that the three-time World Cup winner was receiving end-of-life care. (AFP)