Penn State tight end Garry Gilliam was just starting to see playing time in 2010 when he ran downfield to block an Iowa defensive back at Kinnick Stadium and fell to the ground.

"I knew something had happened," Gilliam said. "With all the adrenaline, it doesn't hurt in the moment. It's real fast, but I knew something had happened. I didn't even try to get up."

Little did Gilliam know how much damage had been done to his left knee. He tore his ACL and MCL and damaged his patellar tendon and lateral meniscus. Compounding matters, an infection developed and postponed surgery five months.

He wondered if he'd be able to play football again.

"That was one of the first questions I asked Dr. (Wayne) Sebastianelli," Gilliam recalled Wednesday. "He told me: 'Yes, you'll be able to get back. It'll be a long path.'

"I trusted that, put my head down and started working."

Gilliam returned to the field last week for the first time since Oct. 2, 2010 when Penn State opened spring practice.

"The knee is 100 percent," he said. "I'm not limited. I'm obviously a little rusty because it's been a long time since I actually played football. Probably the hardest thing was my confidence and trusting that my knee was good to go."

He's one of three probable starters, along with defensive end Pete Massaro and linebacker Michael Mauti, who missed all or a majority of last season with a knee injury. Wilson grad Pat Zerbe, a reserve fullback, also missed last season with a knee injury.

Massaro suffered a torn ACL in his left knee last year during spring practice, nearly two years after tearing the ACL in his right knee in the 2009 Blue-White Game.

"It feels good to finally get back out there," Massaro said. "It wasn't something I was actively thinking about. I was taking it one day at a time and trying to progress with the knee.

"The knee is not 100 percent yet, but I'm making progress and getting better every day."

Massaro said that his knee is about 80 to 85 percent healed and that he doesn't plan to wear a brace when the season starts Sept. 1 against Ohio at Beaver Stadium.

His return will be a boost to the defensive line, which lost All-America tackle Devon Still and end Jack Crawford. Massaro made 31/2 sacks two years ago in his first season, which ranked second on the team.

"Sometimes my head gets in the way more than my knee does," Massaro said. "Other times I can step back and say: 'OK, that part was mental. Or that was rustiness on the part of my knee.'

"There's going to be an adjustment period. If I keep my nose to the grindstone, I know it's going to turn it out all right."

Gilliam made three starts two years ago as a redshirt freshman, catching just one pass for 21 yards. He's expected to play a large role in coach Bill O'Brien's offense, which relied on tight ends Rob Gronkowski and Aaron Hernandez with the New England Patriots.

"I'm really excited about the offense," Gilliam said. "It's obviously a lot different than before. There are a lot of new things we haven't done before. I'm excited to learn and see what it has in store for us."

Gilliam, Massaro, Mauti and Zerbe developed a bond and pushed each other during their rehabilitation.

"Massaro and I talk almost every day about our knees," Gilliam said. "It helps both of us to have that other person to go through it together."