Jasper Brinkley spent the first 4 1/2 months of his rookie year looking to the Minnesota Vikings' experienced and talented veteran defenders for guidance.

When he enters the huddle as the starting middle linebacker on Sunday against Cincinnati, the fifth-round draft pick out of South Carolina will suddenly have Pro Bowlers like Kevin and Pat Williams and Jared Allen looking to him instead.

When his friend and tutor E.J. Henderson went down with a horrific broken leg against Arizona on Sunday, Brinkley instantly became the quarterback of the Vikings' base defense for the remainder of the season.

Now it's time to find out how much he has learned. Veteran Ben Leber likely will help call the plays, but Brinkley will be instrumental in setting the defense before the play.

"I'm definitely comfortable with the scheme," he said. "Coming into it in training camp it had taken a little adjustment coming from another defense. From training camp to the time now, it's all settled in with me."

Henderson had surgery on his broken left femur and will be out for the season. Brinkley had played almost exclusively on special teams up to this point, with some time at middle linebacker in a few blowout victories.

"It's going to be a big void we've got to fill," lineman Kevin Willliams said. "People go down during the season and we've got to count on the younger guys and the backups to step up. ... It's going to be tough to fill his shoes. But somebody's going to have to step in and try."

For now, that someone appears to be Brinkley.

"He will be initially and we'll look at it through the week to see if there's a better combination than that," coach Brad Childress said. "But he's been trained there and he should be just fine."

Henderson went down with a foot injury in the fourth game last year and missed the rest of the season, so the Vikings have been here before. Last year, they signed Napoleon Harris off the street to fill in as the base defense middle linebacker, but played more of their nickel package consisting of just linebackers Chad Greenway and Leber with five defensive backs to compensate.

It seems less likely that the Vikings (10-2) would bring in a veteran free agent to take Henderson's place.

The 6-foot-1, 252-pound Brinkley made an impression early in training camp as a heavy hitter, but this is not the way he wanted to get his first big chance on defense.

"My emotions are I'm still praying for E.J.," Brinkley said. "I know he's going to call me because we are very close because he's like my mentor. I know he's going to be pulling for me."

Henderson and Brinkley share a soft-spoken nature, and a propensity for big hits.

"Well, he weighs 260 pounds and when he hits somebody he does some damage," Greenway said of the rookie. "He's a good player, got a lot of talent, he's worked hard on special teams and been a good player on there. He's proven himself to us as veterans and I think that if he goes in there and gets the start or whatever is going to happen he will be ready."

The Vikings traded up in the fifth round of April's draft to get Brinkley, who was second team All-SEC in his final season at South Carolina after missing most of 2007 with a knee injury.

"We like the things we saw from him," Childress said. "He's got a recklessness and a fearlessness and pretty good instinct for where the ball is."

The Vikings did not do much hitting in camp, but Brinkley quickly made a name for himself by popping the pads a few times in the Mankato heat.

"I'd hate to be the guy he hits," Williams said. "We just get him caught up on a few things and I think he'll be fine filling in. We can't ask him to do everything E.J. did. He just has to play within himself and I think he'll do fine."

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