As spring practice gives way to summer workouts leading up to the start of training camp, Bill O’Brien will likely reveal the first depth chart of 2013.

For a bit of context, a depth chart was released on June 5 last year. Whenever it is made public, it will be much different from the one that Penn State took into the season finale against Wisconsin last fall. One of the most noticeable changes will be a much different list of quarterbacks as the Nittany Lions look to replace Matt McGloin, who led the Big Ten in completions (270), passing yards (3266), and touchdowns (24), but a new stable of signal-callers will not be the only change.

A few pieces to the chart would appear to be stone-cold locks. Glenn Carson is firmly entrenched as the starting middle linebacker for the Nittany Lions. Donovan Smith will be protecting the blindside of Steven Bench or Tyler Ferguson — or maybe even Christian Hackenberg, and Allen Robinson will be the number one receiver, but several other spots remain up in the air.

Below is a look at five position battles other than the quarterback competition that have yet to be decided

Defensive Tackle

What’s at stake? The Nittany Lions must find a nose tackle to replace All-Big Ten selection Jordan Hill and pair on the front four with senior defensive tackle DaQuan Jones.

The Candidates: Three redshirt freshmen in Austin Johnson, Brian Gaia, and Derek Dowrey are in contention for the job along with junior Kyle Baublitz.

O’Brien Quote: “We feel good about what’s there. Again, there’s not a lot there, but there’s enough there, and we just have to do a good job of rotating those guys in and out and make sure we get the young guys enough reps to help them improve and progress.”

Prediction: This could be a classic case of seeing the word OR in the depth chart with two names designated as starters. Jones said the race was pretty much even a few weeks ago. Johnson has been praised throughout the spring, and so has Baublitz. In Saturday’s Blue-White game, Johnson showed why, leading the defense with five tackles and two sacks. This could go a lot of different ways, but it looks like Johnson, the redshirt freshman, could follow a recent trend of great Penn State defensive tackles.

Defensive End

What’s at stake? With Pete Massaro and Sean Stanley gone, the Nittany Lions are searching for someone to play opposite Big Ten Freshman of the Year Deion Barnes.

The Candidates: Upperclassmen Brad Bars and C.J. Olaniyan along with sophomore Anthony Zettel and redshirt freshman Evan Schwan will be in the mix here.

O’Brien Quote: The head coach has not addressed the defensive end spot much this spring aside from saying, “It’s a well coached position,” when answering a question about Barnes.

Prediction: Defensive line coach Larry Johnson Sr. usually likes to rotate linemen when presented with these options, and that should be the case here. Schwan, Bars, and Olaniyan all made their case on Saturday by recording at least one sack. Zettel led this group with four last season. This could go a lot of different ways, and it is tough to handicap a frontrunner right now.

The Secondary

What’s at stake? A lot. If Adrian Amos ends up playing safety as defensive coordinator John Butler said he would, it technically leaves open three other starting jobs.

The Candidates: Malcolm Willis and Stephen Obeng-Agyapong return after starting at safety last season. They are also joined by Malik Golden and Ryan Keiser. Sophomores Jordan Lucas, Da’Quan Davis, and Trevor Williams will be vying for the spots at cornerback.

O’Brien Quote: “We’ve added depth there. We have the ability to go to a five-defensive back personnel group and even a six-defensive back personnel group.”

Prediction: Despite Amos’ position switch, Willis and Obeng-Agyapong should both see the field a lot. Lucas had an excellent spring, winning the Most Improved Player award for the defense, and Williams had a strong Blue-White performance. Both of them could get the starting nod with Davis lurking close behind and rotating in.

Tight End

What’s at stake? Not much was lost here outside of Garry Gilliam moving to offensive tackle. It is more a matter of sorting through several names to find one or two to put on the field at a time.

The Candidates: Kyle Carter, Jesse James, Matt Lehman, Brent Wilkerson, and Adam Breneman — if he plays immediately as a true freshman, will all be in the mix here.

O’Brien Quote: “The one thing that stands out to me about the tight end position as a group is that they are smart guys. That position in our offense is very difficult to learn, second only to quarterback. It’s a very, very difficult position to learn because you’re involved in run-blocking, running routes, pass protections — you’re involved with a lot of things that go on.”

Prediction: James will likely start as the Y tight end, designed for bigger players to block a bit more, while Carter gets the F tight end spot. Lehman should back up James with Wilkerson, who impressed on Saturday with a touchdown catch, seeing time behind Carter. Breneman’s health and progression coming off the ACL tear is the wildcard, but if O’Brien decides to have him play as a true freshman at a position loaded with depth, it means he fully intends to utilize him.

Backup Running Back

What’s at stake? Zach Zwinak looks to be the starter at running back, but will not run the ball 36 times like he did in last year’s finale against Wisconsin.

The Candidates: Junior Bill Belton and redshirt freshman Akeel Lynch should both see carries but are vying for the immediate backup job.

O’Brien Quote: “That’s a very competitive position. As long as I’m the head football coach here, that running back position will always be a competitive position. That’s a day‑to‑day, who practices the best, is the starter the next day, really. That’s how it evolves, because that’s a tough position; that’s a competitive deal. There’s a lot of good players there.”

Prediction: O’Brien plans to use all three running backs here, but that can be difficult in certain game situations, especially when trailing in the second half. Lynch’s size advantage over Belton and strong Blue-White showing could give him a slight edge, but this should play out over the summer.

Unlike the quarterback competition, whoever does not emerge as the starter could still see a decent amount of playing time at all five spots. Fans will not be waiting around for these decisions as they will to see who the signal-caller will be, but that does not make the results unimportant.