Panenka, who currently serves as Bohemians’ honorary president, was transferred to an ICU on Wednesday, according to the club.
“The creator of the legendary penalty kick has been put on life supporting machines,” Bohemians said in a statement.
“We cannot comment on Antonin Panenka’s condition any further at the moment. At the same time, we ask the media and the public to respect the privacy of Mr. Panenka and his family.”
The Prague-based club also issued an update saying Panenka had tested positive for coronavirus on Wednesday.
The former midfielder is known for pioneering a deceptive style of penalty kick that involves chipping the ball gently toward the middle of the goal as the goalkeeper preemptively dives to the left or right.
He famously executed the technique in the final of the 1976 European Championship when Czechoslovakia defeated West Germany in a penalty shootout.
Many players have gone on to emulate the cheeky technique, including Zinedine Zidane for France in the 2006 World Cup final and Andrea Pirlo for Italy at Euro 2012.