B1G shoes to fill: Penn State Nittany Lions

Quarterback Trace McSorley is the front-runner to be Penn State's starter this fall. AP Photo/Gene J. Puskar

Penn State's first three spring practices are in the books. And, like every Big Ten team, the Nittany Lions are working on finding new playmakers.

This young team returns a majority of its starters, but there are several key departures it will have to fill to find success. Continuing with our "B1G shoes to fill" series, here's a look at a few of those important positions and the replacements:

B1G shoes to fill: QB Christian Hackenberg

Why: He was the unquestioned leader of this offense -- and, when he was "on," few were better. Sure, he didn't quite live up to expectations and made his fair share of mistakes. But he didn't have a whole lot wto ork with, either. No matter how you look at it, though, it's obvious Hackenberg's departure is going to be felt on this offense. He engineered six fourth-quarter or overtime comebacks, and he holds nearly every major Penn State passing record.

Replacement candidates: Trace McSorley (6-0, 199, redshirt sophomore), Tommy Stevens (6-4, 219, redshirt freshman), Jake Zembiec (6-3, 202, freshman)

The skinny: James Franklin labeled this an open competition a week ago, but McSorley clearly has the early edge here. After all, he's the only quarterback with game experience and has earned a lot of praise the past two seasons. "He's a guy who gets it," Hackenberg said at this time last year. And McSorley also impressed in the TaxSlayer Bowl loss to Georgia, going 14-of-27 for 142 yards and two TDs after Hackenberg was injured. Stevens and Zembiec will have to make up a lot of ground to seriously challenge the dual-threat.

B1G shoes to fill: DTs Austin Johnson, Anthony Zettel

Why: These two combined to form one of Penn State's best defensive tackle pairings in recent history, and both will undoubtedly be playing on Sundays come fall. Zettel used a unique blend of speed and quickness to work around offensive linemen, and Johnson parlayed his power and athleticism into 78 tackles and 15 tackles-for-loss. (Only safety Marcus Allen and linebacker Jason Cabinda finished with more tackles.) Both were all-conference talents, and they leave a huge void in the middle of the defensive line.

Replacement candidates: Tyrell Chavis (6-3, 295, junior), Curtis Cothran (6-5, 262, redshirt junior), Parker Cothren (6-4, 302, redshirt junior), Kevin Givens (6-1, 267, redshirt freshman), Antoine White (6-2, 283, redshirt sophomore), Robert Windsor (6-4, 285, redshirt freshman)

The skinny: Cothran and Givens were forced to move from defensive end this spring to provide more depth for the interior, so it's clear tackle is the biggest question mark on the defense. Cothren is the front-runner to lock up one of the spots, with White and Chavis likely battling for the other. Chavis, a junior-college transfer, won't join the team this spring -- so White gets a huge opportunity to impress the staff right now. He played in 10 games last season, and his role is obviously expected to increase this season even if he doesn't win the starting job.

B1G shoes to fill: Carl Nassib, DE

Why: Penn State's version of "Rudy" brought more to this team last season than anyone -- even Nassib -- expected. The former walk-on set the single-season school sacks record (15.5), earned numerous All-America honors and won the Lomardi Award. He wasn't the loudest player on the field, but he sure let his play do the talking. He forced six fumbles, the most by a Penn State player in more than a decade, and he added 19.5 tackles-for-loss. That's a lot of production to replace.

Replacement candidates: Torrence Brown (6-3, 257, redshirt sophomore), Ryan Buchholz (6-6, 260, redshirt freshman), Kam Carter (6-4, 305, redshirt freshman), Evan Schwan (6-6, 252, senior), Shane Simmons (6-3, 230, freshman)

The skinny: Brown and Schwan are the most experienced candidates here, and the most likely to compete for Nassib's spot. (Simmons was the headliner of the 2016 recruiting class, but he won't enroll until summer.) Schwan isn't flashy, but he has played in 30 games and has been a relatively dependable backup. Brown has a much higher ceiling, and has shown he can be explosive. In fact, half of his 11 stops last season came behind the line of scrimmage. (He had 5.5 tackles-for-loss.) Brown is a potential "sleeper" on this defense, and he's worth keeping an eye on this spring.