It's never too late -- or too early -- to see what we learned from this season and also look ahead to next season. So, we've started breaking down each position on the Nittany Lions.

Up today: Defensive line.

REWIND

Expectations entering the 2013 season: Believe it or not, more question marks surrounded the defensive tackles than the defensive ends. Although Gil Brandt named DaQuan Jones the best senior DT in the country, the senior was still an unproven commodity. And the starter alongside him -- Kyle Baublitz or Austin Johnson -- was widely considered a liability.

Deion Barnes had already garnered NFL hype, and 10 sacks didn't seem out of the realm of possibility for the reigning Big Ten freshman of the year. The line wasn't expected to be as good as 2012, but it was still expected to be in relatively good shape.

How they fared: Jones was the best player on the defense, finishing fifth in tackles (56), first in stops in the backfield (11.5) and making it difficult for any tailback to find room up the middle. The combination of Johnson/Baublitz fared better than most thought, too.

But the defensive ends? Well, Barnes might've been the most disappointing player on the team. He followed up his strong freshman season with just four sacks, and he struggled with his run-defense. Bill O'Brien didn't start him for a game or two to send a message. C.J. Olaniyan played especially well in the second half of the season, although his forte wasn't exactly setting the edge, either. Still, he wound up with 11 tackles-for-loss and a team-high five sacks, four quarterback hurries and three forced fumbles. Anthony Zettel also played well in spots.

What we learned: Barnes isn't the first-round NFL lock we thought he was. At least not yet. He utilized his speed a lot in 2012, but he was just outmuscled in 2013. He needs to add weight and get stronger before his production matches his freshman season. Teams are aware of him now, so he's not taking anyone by surprise. He's going to be a huge factor on this team moving forward, and we learned he needs to add some tangibles before he reaches double-digit sacks.

Grading the position: B. No, this group wasn't as strong as 2012. But it was still the best group on the defense in 2013 and often set the tone. When the defensive ends set the edge, fans knew the team would be in OK shape. When they didn't? Disaster loomed. They were able to pressure quarterbacks in the conference season, and -- outside of the Ohio State game -- the run-defense performed well in the Big Ten.

FAST FORWARD

Key losses: Jones and Baublitz. PSU's top three DEs return, but it loses two of its best three DTs. The interior was a strength in 2013, while the ends were more of an issue. In 2014, that situation's a bit flip-flopped.

Position stock watch: Trending downward. Jared Odrick, Devon Still,Jordan Hill, Jones -- PSU has had a lot of luck finding future NFL DTs to step in one season after another. But that might end in 2014. If Barnes can improve his production from his freshman season and Olaniyan can make some strides, then it won't be all bad news. But when you lose the best player on your line -- and on your defense -- that usually doesn't work in your favor. Couple that in with Baublitz's decision to leave, and depth at defensive tackle will definitely be a concern.

Key to next season: Production of the No. 2 DT. It's as simple and as difficult as that. Johnson will return as a starter, but who will start alongside him? The early favorite is probably Zettel, who could move from DE. But incoming juco Tarow Barney (Bainbridge, Ga./Northwest Mississippi C.C.) or freshman Thomas Holley (Brooklyn, N.Y./Lincoln) playing immediately isn't a total stretch either. If PSU finds a solid replacement, this line is likely in store for another "B" grade next season. If it doesn't? It's going to have to deal with an Achilles' Heel all season. Just ask Trevor Williams how that worked out.