The Nittany Lions (4-1, 1-1 Big Ten) head to Michigan (2-4, 0-2), with the Wolverines' stadium 150 miles from Zettel's house in West Branch.
Zettel left the state for Penn State in 2010 as Michigan's No 3-ranked high school recruit, choosing the Lions over Michigan State and Michigan, among others.
Zettel said it was a tough decision and a pretty big deal to the schools in his home state. Michigan State was his second choice.
''A lot of fans were mad but more fans would have been mad if I'd have gone to Michigan or Michigan State because they're opposite fans,'' he said. ''It was hard to leave, but it wasn't. When I got to Penn State, I realized this school was the best school for me.''
The 6-4, 276-pound redshirt junior is tied for second in the Big Ten in tackles for loss with seven. His 17 tackles are fourth best on the team.
He'll share his homecoming with defensive end C.J. Olaniyan, who grew up just 50 miles from the Michigan campus in Warren.
They'll join end Deion Barnes and tackle Austin Johnson in attempting to stop Michigan quarterback Devin Gardner. The Wolverines have struggled offensively but haven't abandoned the running game, despite the loss of tailback Derrick Green to a broken collarbone.
''They're going to try to run the ball on us and I think the D-line and linebackers and safeties are going to step up and meet the challenge,'' Zettel said.
Gardner threw for 240 yards and ran for 121 against Penn State last year in a 43-40, four-overtime game the Wolverines lost after leading by 10 points. He has 911 passing yards this season but has been limited to 131 rushing.
''It's more a mental thing than a physical thing,'' Zettel said. ''By the end of the play you need to be in your gap so he can't leak out and run.''
Zettel, who trains in martial arts in the offseason, has been on a ticket run this week and is competing with Olaniyan to see who can secure the most for their Michigan family and friends.
''C.J.'s got me right now but we're battling for it,'' said Zettel, who needs about 30 tickets. ''It's going to be a great experience. All my family . everybody's been waiting on this game on the Penn State schedule. It means a lot to me to have a lot of support.''