Bednarik, 85, was reportedly admitted earlier in the week with shortness of breath, according to the Morning Call.
Despite the “serious” condition, Bednarik’s son-in-law Ken Safarowic says his father-in-law remains strong.
“His heart is as strong as when he was playing and he is conscious and he just wants to get out of there,” Safarowic told the Morning Call.
"I'd like to say he's resting comfortably, but I don't know that Chuck can ever rest comfortably. That's just the way he is."
Safarowic told Fox Sports that he expects Bednarik to be released from the St. Luke’s in the next day or so.
Bednarik starred at the University of Pennsylvania before being picked by the Eagles with the No. 1 overall pick in the 1949 NFL Draft.
"Concrete Charlie" -- a name given to Bednarik for his crushing hits (just ask Frank Gifford) and two-way play -- would win two championships (1949 and 1960) while anchoring the Eagles offense and defense for more than a decade.
The eight-time Pro Bowler retired in 1962 and was inducted into the Pro Football Hall of Fame in 1967.