The two Ohio State juniors, both highly touted prospects coming out of high school, spent the first two days of fall practice at middle (Mike) and strong-side (Sam) linebacker, respectively, and have no intention of letting their grasp on those spots slip away.
For Klein, that means getting back on the field after missing much of spring practice because of a hamstring issue.
"It slowed me down and it was unfortunate, but I'm back," he said. "The biggest thing when you get hurt is just getting back on the field and then taking care of yourself.
"I just watched film and watched the guys. It pisses you off watching everybody else play, but it fueled the fire."
Sabino's wait has been longer.
He enrolled early in 2008 and turned lots of heads that year while backing up the likes of three-time All-American James Laurinaitis. After losing battles for starting jobs each of the past two years, he ended up taking a redshirt season in 2010 to save a year of eligibility.
Now penciled in at the Sam, he said he is starving for some action.
"When I got here I definitely wanted to contribute somehow," he said. "I had James Laurinaitis in front of me, which is somebody I wanted to learn from, obviously one of the best linebackers ever to play college football, but I never for a second doubted my ability. I definitely wanted to come in and contribute."
While both could play when the team is in its 4-3 base defense, one is likely to come off the field when Ohio State goes to its nickel package and brings Tyler Moeller into the game.
Sabino held down the Mike spot in the nickel defense (alongside Sweat) the first two days, but he knows he cannot get complacent.
"I think there's always a competition. That's what makes us good here, so I'm not taking any days off," Sabino said. "I know Storm can jump right in there and play just as good as Sweat. Really anybody can jump in there and we wouldn't miss a beat."
Klein and Sabino not only face the task of handling starting assignments for the first time, they are trying to juggle breaking in a few new teammates and a new position coach.
Digesting the playbook is the hardest thing young linebackers have to deal with early in their careers.
"Everybody has the physical ability to be here," Klein said. "If they can get in there and listen to what the older guys are saying, that's how they'll pick it up."
All of the linebackers are getting use to listening to a new voice in their room as well since former Buckeye Mike Vrabel joined the coaching ranks in June after 14 years in the NFL.
"He brings a lot," Sabino said. "He brings experience. I mean he played last year in the NFL, so what can he tell you that you don't think will work? All of it is going to work because it worked for 14 seasons in the NFL. He demands a lot of you, but he's a players' coach. He's going to pat you on the back when you're doing good, but he's not going to let you get complacent. I think that's what we all need."
Vrabel has also been the source of amusement for his new pupils as he gets used to "civilian life."
"Yesterday he was fired up, trying to get on the field, and we were like, 'It's over for you. You've gotta end that. You're coaching us now,' " Sabino said with a smile. "But I like him a lot and we're going to have a lot of fun this year."