The president of the Greek FA, Sofoklis Pilavios, visited Greece's training base in Legionowo during a scheduled press conference to express his condolences for the passing of Panagoulis, who led the country to their first European Championship (1980) and World Cup (1994) finals.
"I express my condolences on behalf of the Greek FA and all football fans for the passing of Alketas Panagoulias," Pilavios said.
"He was a very important person for Greece as he led the national team of his country to their first European Championship and World Cup."
In addition to the armbands, Pilavios has asked Uefa to hold a minute's silence before the game to pay tribute to Panagoulis' memory.
"In Friday's match [against Germany] we have asked from Uefa for a minute of silence to be observed," Pilavios explained. "Our internationals will sear black armbands."
Kyriakos Papadopoulos and Giorgos Samaras also appeared before the press and gave their opinion on the upcoming match against Germany.
"This match is special for me because I play in Germany [for Schalke]," Papadopoulos admitted. "I know our opponents. I have played against them many times.
Celtic striker Samaras added: "We will not play for ourselves. We will play for our country, for the 11 million Greek people. We want to make them smile, to go out on the streets and celebrate."
Greece will face Germany in the second quarter-final game on June 22.