The Penn State senior defensive tackle and his teammates might have to stop both Indiana quarterbacks on Saturday - a tricky proposition since their skills are so different.
''Sudfeld, he can sit in the pocket and whip the ball. He's a very, very efficient passer,'' Zettel said. ''Diamont, the kid's an athlete. He's going to set their offense up in the best way he can using his feet.''
Just like he did last week against No. 1 Ohio State.
Diamont nearly brought the Hoosiers back from a 14-point deficit in relief when Sudfeld, the team's 6-foot-6, strong-armed starter, was knocked from the game in the third quarter.
Zettel wasn't surprised to see Diamont's 76-yard touchdown run with 10 minutes left that cut Ohio State's lead to a touchdown. He also wasn't surprised to watch Diamont lead a nine-play drive to the Ohio State 9-yard line before an errant snap sealed the Hoosiers' loss.
Diamont nearly led a comeback against Penn State a year ago. With Sudfeld injured, Diamont ran for 58 yards and five first downs, but Penn State escaped Bloomington with a 13-7 win. It didn't go as well for Penn State the previous season when Sudfeld picked the Nittany Lions apart for 321 yards and two touchdowns in Indiana's only win in the series.
But Sudfeld is far from a lock to play on Saturday. He aggravated an ankle injury against the Buckeyes and will have to be cleared to play by doctors.
He'll also have to be mobile enough to escape danger, which can come from any angle against Penn State.
The Nittany Lions are second in the country with 21 sacks and third in tackles for loss with 46. Defensive ends Carl Nassib and Garrett Sickels have come on strong while Zettel and Austin Johnson have been equally effective in the middle.
''If Nate's healthy and he can protect himself and play, he's going to play,'' Indiana coach Kevin Wilson said.
Which quarterback plays will affect Penn State's defensive backs, too.
Coach James Franklin hasn't been pleased with his secondary's tackling the last two weeks and different quarterbacking styles will call for different approaches from a secondary that's struggled to bring down ball carriers in the open field.
Shoulder tackles and poor pursuit angles plagued Penn State in its 20-14 win against Army, particularly when quarterback A.J. Schurr burst down the sideline past sophomore cornerback Grant Haley and senior safety Jordan Lucas for a 56-yard touchdown run in the fourth quarter.
''We're the last line of defense so we gotta be the most reliable and wrap up as best as we can,'' Haley said.
Especially if Diamont scrambles into the second level and if Sudfeld plays and spreads the ball around to a pair of 6-foot-4 receivers in Simmie Cobbs Jr. and Ricky Jones. Both have 21 catches and big size advantages over Penn State's defensive backs.
''We gotta have respect for both of them,'' Haley said.