Stopping Northwestern quarterback Dan Persa will be the Michigan football team's top priority Saturday, but not its only concern.

Wolverines coach Brady Hoke said this week his team needs to shore up its special teams — particularly the kick coverage unit, which has been the one continued sore spot during Michigan's early-season resurgence.

The No. 12 Wolverines are 5-0 and 1-0 in Big Ten play heading into their first road game Saturday at Northwestern (7 p.m., BTN). But with their previously one-dimentional offense showing balance and previously toothless defense getting penetration and stops, the kick return game is Michigan's biggest remaining flaw.

Freshman kicker Matt Wile with Michigan football coach Brady Hoke earlier this season.

Melanie Maxwell | AnnArbor.com

Michigan is averaging 18.6 yards per kickoff return, among the nation's lowest. On the flip side, it is allowing 21.8 yards per return.

The Wolverines are netting just 41.7 yards per kickoff, third worst in the Big Ten.

Most telling of all: They lead the country in 30-yard returns allowed (eight).

Even Minnesota, which was beaten 58-0, bumbled several kickoffs and committed six special teams turnovers, returned a 96-yarder for a score. It was called back because of a penalty.

The Gophers also had returns of 28 and 34 yards.

Those woes have become a point of emphasis at Michigan's practice.

"We always do coverage teams on Tuesdays, plus return game on Wednesday — plus we always do another 5-minute segment with the punt, because that's such an important play in football, statistically, if you believe in statistics," Hoke said.

Hoke has said numbers — such as Michigan's No. 2 ranking in scoring defense or No . 31 ranking in total defense — mean little to him. Obviously, though, these numbers do hold some weight.

"We work pretty physically on it," Hoke said. "We're going to do some kickoff live at the end (Wednesday), and we've got to send a message."

This weakness could be exacerbated against Northwestern.

The Wildcats feature Venric Mark as their punt and kick returner, and he's one of the league's best. The sophomore receiver averages 17.3 yards per punt return and 25.3 yards per kickoff return.

Northwestern leads the league in punt returns and is fifth in kickoff returns.

"When you look at their returns on punt and kickoff, they're significantly higher than the average," Hoke said. "I think their returner is very good, quick, and he does punts and kickoffs. We've just got to be more sound."

One source of Michigan's trouble could be the ball placement of true freshman kicker Matt Wile. He has improved since the start of the year, but still leaves too many kicks in the center of the field.

"I think that's always part of it," Hoke said. "When we've had really good locations, usually we've had good coverage.

"I can think back last week, there were three of them that were really located pretty daggone well — and two of them, one was in the middle of the field where we didn't want it, the other one was right middle, which wasn't over far enough."

Kyle Meinke covers Michigan football for AnnArbor.com. He can be reached at 734-623-2588, by email at kylemeinke@annarbor.com and followed on Twitter @kmeinke.