MANKATO, Minn. - As Vikings training camp continues in Mankato, one of the many questions for the team goes back to the linebacking core.

How will they replace the recently retired Chad Greenway?

It might be hard to believe, but at just 25 years old Anthony Barr is now the Vikings grizzled veteran at linebacker.

"I just try to lead by example, do my job the right way, hustle to the football, and hopefully the guys see that and it inspires them to do the same," he says.

Barr begins his fourth season in the NFL with a little something extra to prove. Not only is it a contract year, but Coach Zimmer openly questioned his effort last year.

"I just gotta take it up another level and create more turnovers, create more big plays, and help the team win," he said.

"He comes in every season with a goal in mind and he tries to achieve it and he doesn't let anyone stop him," says the Vikings' reigning leader in tackles, Eric Kendricks.

Unstoppable at times last year, Kendricks knows that both he and Barr will have more on their plate without Greenway in the picture.

"We've got to step up, we've got to be leaders," he said. "Obviously we can't replace somebody like Chad Greenway, but we can try, and we can just be the best version of ourselves."

While it might be a collective effort to replace Greenway's leadership, one of the most interesting battles in camp is between Emmanuel Lamur and Edmond Robinson for Greenway's spot.

"They're battling through camp, they will continue to battle through camp, and again, we'll look for them to see who's the most consistent every day," said Defensive Coordinator George Edwards.

That still remains up in the air as both Robinson and Lamur take turns with the first team defense.

"I think we're almost like a similar player, I think he's just a little more experienced than I am," said Robinson. "He's going into his sixth year, I'm going into my third, he has a lot more playing time than I have in the previous years."

"It's going to be a very fun competition," Lamur said. "At the end of the day, like I said, I'm just trying to get better and it's going to be very exciting."

It's an exciting but crucial question the Vikings must answer before the season begins.