But you don't have to squint too hard to see potential trouble on the horizon at the position. Zettel is in his final season of eligibility, as is backup Tarow Barney. If he has a strong year, the 6-foot-4, 325-pound Johnson could well make an early exit to the NFL Draft.
The only two other scholarship players in the program now are rapidly rising redshirt sophomore Parker Cothren and promising redshirt freshman Antoine White. The Class of 2015 features only one natural defensive tackle -- Wisconsin native Robert Windsor.
That all means defensive tackle is a position -- perhaps THE position -- of need for James Franklin's Class of 2016.
To help address this, the Nittany Lion staff is taking a look at the junior college ranks. Last week, PSU offered Nassau (N.Y.) Community College DT Tyrell Chavis while he was in town to check out the Blue-White Game.
Chavis is a 6-3, 300-pounder from Richmond, Va., who began his college career by redshirting as a true freshman at Virginia in 2013. When things did not pan out for him there (more on this later), he moved on to Nassau.
He enjoyed being back in a major-college atmosphere last week.
Driving up to the stadium and seeing all of the fans and the amount of support they have, it was good, Chavis said. The fans were overwhelming. It was a nice atmosphere.
Just coming back to this level, it's nice to be noticed, he added.
It was difficult to miss Chavis. Of the dozens of recruits milling about the sideline, he clearly was older and more physically put together than the rest. He received the scholarship offer before the game, along with a specific message from the Penn State staff.
They want someone who can come in and start and be a presence early, he said. They need somebody with more experience so they can bring in some freshmen and redshirt a couple of them.
Chavis is expected to graduate from Nassau in December and intends to enroll at a four-year school in January. He will have two years of eligibility remaining with no redshirt available.
His experience is not limited solely to the football field. He has also done his share of traveling.
He was a standout defensive tackle at Varina High in Richmond, then signed with Virginia in 2012. On the advice of the UVA staff, he attended Fork Union Military Academy the following fall.
There, he played on the same team as a quarterback named Christian Hackenberg and a receiver named Josh McPhearson. Hackenberg has been PSU's starting QB the last two seasons and McPhearson is a walk-on receiver for the Lions.
It was nice to see my old friends again, Chavis said of re-uniting with Hackenberg and McPhearson last week. Those are my boys. That's just a bond we'll always have.Chavis with PSU D-line coach Sean Spencer prior to the Blue-White Game.
Chavis moved on to Virginia in 2013. But head coach Mike London had shuffled his staff from the one that recruited Chavis -- which included firing defensive line coach and recruiting coordinator Jeff Hanson, as well as defensive coordinator Jim Reid.
It was nothing academic, Chavis said of his decision to leave UVA after redshirting in 2013. The defensive line coach got fired and the defensive coordinator got fired. So the guys who recruited me were gone. I just didn't feel like it was the right fit for me anymore.
As he goes through the recruiting process again, this time he intends to be patient and make sure he finds the best fit. That will likely include another visit to Penn State.
I got to sit and talk to the coaches a little bit, he said. But I plan on coming back in the future to sit down and talk some more.
The only other visit he has planned at the moment is a trip to Louisville in late May.
Right now, I'm on the open market, Chavis said. I'm looking at whoever is interested in looking at me. I don't have a timetable yet. I'm just going to take my time.
Penn State has landed scholarship prospects from Nassau before, most recently signing offensive lineman Nerraw McCormack late in 2007. Rich Mauti (1973) and Mike Alexander (1985) also attended the school. (McPhearson spent two seasons there before walking on at PSU in January.)
At this point, there is no telling if Chavis will join that group. But it can be said that his first experience with Penn State was a good one.
Penn State, I feel like is a nice school, so I wanted to take a visit there, he said. When my coach (at Nassau) told me they were interested, we decided to get something scheduled. I felt like the spring game would be the best time to see the place.
It was a nice feeling, he added. They offered me before the game, so it was great to get the offer and then watch the team in person.