Penn State vs Northwestern: five storylines to follow

Penn State looks to begin its Big Ten season 2-0 -- but it won't be easy.

The Nittany Lions (3-2) roll into homecoming weekend on a three-game winning streak. Coach Bill O'Brien calls Penn State's opponent -- No. 24 Northwestern -- the toughest team the Nittany Lions have faced yet. And for good reason.

Pat Fitzgerald's Wildcats are ranked in the AP Top 25 for the first time since 2008 and they are looking for their first 6-0 start since 1962.

Can Penn State's defense slow down the Wildcats, who set a school record with 704 offensive yards last week? Will Matt McGloin continue his early success? Here are five storylines to follow:

Containing Colter: Defensive coordinator Ted Roof certainly had his work cut out for him this week. Northwestern quarterback Kain Colter is the most dynamic, athletic athlete the Nittany Lions faced yet. And he plays all over the field. After playing the first four games solely as a quarterback, Colter lined up at wide receiver and ran the ball last weekend against Indiana. The results? You could say they were pretty successful. As Northwestern set a school record for yards (704), Colter ran for four touchdowns and picked up 292 all purpose yards. For Roof and Co. to be successful, they'll need to know where Colter is on the field at all times.

Wildcat killer: Matt McGloin has been stellar for the Nittany Lions so far this season -- and he's been stellar in the past against Northwestern. In two career games against the Wildcats, McGloin has thrown six touchdowns without an interception. He's only taken one sack in that span. Currently, Northwestern ranks 109th in the nation in pass defense (289 yards per game).Could McGloin be poised for another standout performance?

Who is No. 1? Sophomore Bill Belton entered the season as the Nittany Lions' No. 1 running back. After he was injured in the season-opener against Ohio, Penn State replaced him by committee. Each week, a new back stepped up. Last week, against Illinois, it was Zach Zwinak who shined. The sophomore ran for two touchdowns and became Penn State's first 100-yard rusher this season. Belton is fully healthy now, which leaves O'Brien's offense in this conundrum: Who gets the majority of the load? Belton is faster and shiftier while Zwinak is more of a pound-through-the-defense kind of guy. They complement eachother well, but can the workload be 50-50?

Keeping it clean: A highlight for Penn State five games into the season has been its ability ot hold on to the ball -- and create turnovers. After posting a minus-three turnover margin in the season-opening loss to Ohio, the Nittany Lions have been solid -- if not spectacular -- in this category. Over the last four games, Penn State has a plus-10 differential in turnovers, giving the ball away only once. Northwestern, meanwhile, committed three turnovers against Indiana. Turnovers create opportunities, and if the Nittany Lions keep it up, they'll have an opportunity to record a big win.

Third times a charm: Here's another category Penn State has made great improvements on since its first two losses: third down defense. The Nittany Lions allowed Ohio and Virginia to convert a combined 22 of 36 (61.1 percent) of third downs. Since then, Penn State has held its past three opponents to just 11 of 42 (26.2 percent) of third down attempts. The Nittany Lions can't regress here, though it will be hard. Northwestern has the most dynamic offense Penn State has seen yet.

-Emily Kaplan