"I've been looking forward to it for a while," said Byers, who is on active duty in the Navy and still could be deployed at any time.
Byers tried out for the Penn State football team two years ago, when he was 25. Many of his teammates now are 18.
At the Lasch practice field, the 6-foot, 246-pound Byers has one job: pound as hard as he can to make sure the defense is ready for the opponent.
"A lot of people look up to P.J.," said Marple Newton's Pete Massaro, a senior defensive end. "I would definitely say P.J. is one of the hardest workers on this football team."
The work ethic is inherent in everything Byers does. Before enrolling at Penn State, he spent three years stationed at Pearl Harbor and two years in San Diego as a diver. He has searched for underwater mines and has done demolition work with explosives.
On Tuesday, Byers was especially pensive. It was the 11th anniversary of the Sept. 11 terrorist attacks and the fullback recalled living through it as a sophomore in high school. It was one of the reasons he decided to join the military.
Byers is joined by defensive end Brent Smith, a 26-year-old freshman, as members of the Penn State football team with military experience. Smith served in the Marines for eight years, including two tours in Iraq.
"I think our guys look up to them for what they stand for and what they do," said Penn State coach Bill O'Brien.
What Byers does now is play football, a sport he loves. He weaves his military life into life on a major college team. He looks at the season as a mission: Win every game, one game at a time.
"As one team, we work toward that mission," Byers said. "Just like a dive team would."
When he graduates Penn State, he will become an officer. Rick Slater, a former Nittany Lion and 19-year Navy SEAL, took a similar path.
O'Brien brought Slater to speak to the team this offseason. His speech, which centered on hard work and leadership, resonated with the players.
Byers asked Slater for a copy of it. One day, he will recite it to his unit.
For now, he keeps it in his locker.