Erin Henderson's hunger is evident in his eyes. Mike Singletary senses it. And who better to translate a look than a legend whose own career was hallmarked by a bug-eyed stare that carried him around the field with so much fury.

Few ever have excelled at middle linebacker with the combination of aptitude, ferocity and purpose Singletary used to become a Hall of Famer. So yes, his judgment carries credibility. And since joining the Vikings as an assistant in 2011, he has believed big things are within Henderson's reach. If only Henderson can master the calibration needed to balance his ambition with patience, intensity with composure.

Still, as a starting point, Singletary always has been struck by Henderson's disposition.

"Erin's a really bright guy," Singletary said. "But he has a nasty temperament about him. And I like that. He can get ticked off. And he has an ability to use that to come up big."

Yes, on a daily basis, Singletary can be demanding on the now 27-year-old Henderson, insisting every minuscule fundamental be executed exactly. And sure, at times, Henderson will snap back at his position coach's requests. But as Henderson charges toward the start of the 2013 season with designs on being the Vikings' starting middle linebacker for years to come, he knows a huge opportunity has arrived.

So he's using Singletary as a resource — to refine his footwork and better learn his reads. And Singletary issues a reminder for how Henderson can thrive in his new role.

"Just be Erin," he said. "That's it. He's good enough. He's talented enough. He's smart enough. Just do your job and don't allow it to go any further than that. Be Erin. Make the plays."

'More than ready'
After five seasons, the past two starting on the weak side, Henderson now has a firm grip on the starting middle linebacker duties — at least for now.

And it's that asterisked disclaimer that still annoys Henderson.

At least for now. At least for now.

First came widespread predraft speculation about the Vikings' interest in Notre Dame's Manti Teo. Then came the outlandish rumblings about Brian Urlacher possibly coming to town. And those were followed by the Vikings' unexpected summer courtship of Desmond Bishop, whom the Packers set by the curb in mid-June.

Henderson heard the chatter, ignored what he could and continued working to strengthen his grip on the job.

"He's taken it personally," Pro Bowl teammate Chad Greenway said. "But in a good way, in the sense that he wants this opportunity and in many ways he knows he's earned it."

With Friday's preseason opener approaching, Henderson can exhale. Teo is now a Charger, Urlacher is retired and Bishop, assigned to the weak side at the opening of camp, still is working with the second team — at least when his pulled groin isn't sidelining him from practice, as it did Monday.

So yeah, the middle linebacking duties are Henderson's. And he hopes the "at least for now" part of the discussion is disintegrating.

"I know what's needed at the position," Henderson said. "I know what's expected of me. I'm more than ready for this."

Under control
Singletary said he thinks Henderson's intelligence can be an obvious asset. And Greenway said the respect hurdle has been cleared with the defense already rallying around Henderson.

"Erin's best physical attribute is just his ability to play the game," Greenway said. "He might never blow you away with his speed or talent or his ability as a big hitter. But he's just a good, instinctive football player. This comes natural to him.

"Because he can make plays in space, he can do all the things we need him to do. And most of all, the more he plays, the better he gets."

Coach Leslie Frazier remains more measured, still calling for leadership growth. More than that, Frazier wants Henderson to prove he can heighten his discipline. At times, Henderson's Achilles' heel has been his want to deliver splash plays at the expense of sticking to routine but more important duties. Henderson's eyes, he admits, have had a tendency to "get too big," causing him to chase plays that weren't his to make.

"At middle linebacker you have to be so much more disciplined than you do as an outside backer," Frazier said. "So we just have to continue to harp on him about putting your eyes when they're supposed to be."

Still, in many ways Henderson believes the move inside actually will mitigate that weakness. On the weak side, he said, it took him time to understand the sacrifices he had to make to keep the defense humming. But now?

"I'm allowed to be more free," he said. "I'm in the middle of things. I'm in the action. I'm able to go both ways and be in the mix all the time. So it's not really me having to go search to make a play somewhere else, because usually everything's funneled to me."

A golden opportunity has funneled Henderson's way. He recognizes that. He's studying for the part. And the fire in his eyes has a chance to light a wick for a breakthrough.