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The juxtaposition between audio and video was striking. With "[Hail to] The Victors'' being played by the Michigan Marching Band after the Wolverines' 29-7 victory on Saturday, Michigan State players left the field and trickled down the tunnel at Michigan Stadium toward the visitors' locker room. Suddenly, a few Spartans players heard a ruckus and turned back up the tunnel to see what was going on.

There, video shows, an MSU player swung his helmet like a club to hit the head of Michigan defensive back Gemon Green, who wasn't wearing a helmet. Seconds earlier on a different video, a handful of Spartans were shoving and punching Wolverines defensive back Ja'Den McBurrows, who entered the tunnel before his teammates and amid the MSU players.

"The Victors'' played on as team personnel tried to funnel MSU players into their locker room, and soon Michigan players filed in, shouting across the tunnel at the Spartans.

"It's sickening to watch the videos,'' Michigan coach Jim Harbaugh said Monday. "… There needs to be accountability. There needs to be a full, thorough, timely investigation. I can't imagine this won't result in criminal charges.''

Green and his family are planning to press charges, ESPN reported, and the University of Michigan Police Department is investigating the melee.

Michigan State responded Sunday by suspending four players indefinitely, followed by four more on Monday. Three were starters, including edge rusher Jacoby Windmon, safety Angelo Grose and defensive end Zion Young. Coach Mel Tucker also apologized for his players' actions.

Some 650 miles away, Gophers coach P.J. Fleck noticed the events in Ann Arbor and on Monday was asked about what steps his program takes to avoid such situations when tempers run high between powerful athletes whose job is to ram into each other for more than three hours.

"I can't speak for anybody else, nor can I say we're perfect. I can say we do have processes in place for that,'' Fleck said. "Our operational team and our strength and conditioning team are responsible for setting up a wall no matter where we have to go. And I'm always the last one in [the locker room].

"Our operational team will lead [the players] in, the strength staff will be in the middle, and I'll be at the end, and then they all form a wall on the outside.''

Keeping opposing players separated is essential. That's not always easy depending on the stadium. At Michigan Stadium, built in 1927, there is only one tunnel to the locker rooms, and both teams use it. At Huntington Bank Stadium, the Gophers and their opponents use separate tunnels located near the opposite end zones.

Fleck points to potential problems when teams have to cross from their sideline to the opposite side of the field to go to their locker rooms, creating a collision course. "There's a cross-tunnel issue,'' he said. "A lot of issues have happened on the field when people cross.''

He also mentioned how plans that have teams entering the field at staggered times don't always come off perfectly.

"There are plenty of times when you're coming on the field from halftime where you've got to come out at a certain time or you're told to come out a certain time, and the team across from you is coming out,'' he said. "Their initial wave comes out at the right time, but then there are the joggers in the middle and the walkers at the end. We might have to back it up to two minutes just to make sure we don't cross paths with another team.''

There's no single answer to prevent incidents such as the one in Ann Arbor from happening. Here's a starting point, though: Respect your opponent. Without them, there is no game.