But he's not at home moping or feeling bitter about his situation, said quarterbacks coach Jay Paterno, who has been to 12 previous bowl games as a member of his father's staff.
"His spirits are really good," the younger Paterno said Friday before the Nittany Lions practiced at Bishop Lynch High School for their TicketCity Bowl game Monday against Houston. "He's a fighter. You know what his character is and what his makeup is. He fights. He never gets down. It's about the next challenge, and this is another challenge for him."
Jay Paterno said that rather than complain about what had happened to him, his father mentioned during his birthday party how thankful he was that his family was in good health.
"Joe is one of those guys who looks at the bright side of everything," he said. "So whether he's bitter or not, you'd have to ask him."
Joe Paterno was fired four days after former assistant coach Jerry Sandusky was indicted on charges of sexual abuse, a case that now involves 10 boys. Paterno was told of one alleged on-campus assault in 2002 by then-graduate assistant coach Mike McQueary, now a full-time member of the staff who is on administrative leave.
Paterno's testimony before the grand jury was read into evidence at the Dec. 16 preliminary hearing for former athletic director Tim Curley and former university vice president Gary Schultz. He told McQueary, "I need to tell people what you saw," but he was criticized for not doing more to facilitate the apprehension of Sandusky.
Jay Paterno indicated that his father would be exonerated once "everything comes out, and once everybody sees everything that's happened."
"I think people realize that, without getting into any specifics, Joe conducted himself in a way that's consistent with his character, and I think we'll see that eventually," he said. "There's been some criticism as to what he did and didn't do and I think that'll all come out."
Health-wise, Paterno said his father was doing "very, very well" but that he hasn't been able to take walks with his son since he fell in his home on Dec. 3. He said cancer treatments make his father tired.
Joe Paterno has received visits from some players and coaches. Offensive coordinator Galen Hall said he visited him last week and described him as "doing fine, looking good. He's very much the same as he was before."
Interim head coach Tom Bradley said he hasn't talked to Paterno since the night he was fired, and was rather tight-lipped in an ESPN interview when asked about his former boss' health, saying that information should come from the family.
"I think I've picked up the yelling for him so I've kind of been his voice out there at practice and getting after the guys pretty good," he told the network. "But it's a little different not seeing Coach out here, that's for sure."
That's a shared feeling. But Jay Paterno decided to joke about it when asked how much his dad was missed.
"It's really strange," he said. "Usually, if my wife and I wanted to go out to dinner [at a bowl], we'd take the kids and dump them off with my parents. They're not on the trip, so that's been a major drawback, maybe the biggest. But yeah, it's been strange."
Contact staff writer Joe Juliano at 215-854-4494
or @joejulesinq on Twitter.