It’s easy for Gainesville’s A.J. Johnson to flip the switch. He knows there’s an appropriate time and place for everything.

During the day, Johnson is a mild-mannered junior that instinctively says “yes ma’am” and “no ma’am” when called upon in the classroom. He says that respect for authority was instilled from a young age by his mother, Vivian Drake.

“I was brought up to always be respectful,” Johnson said. “My mom made sure of that.”

However, once Johnson steps on the football field, well, you could say he is the authority figure.

The starter at middle linebacker for the Red Elephants (14-0) has made a name for himself as a punishing tackler, a menace to a quarterback’s general well-being, and one of many driving forces behind Gainesville’s trip to Saturday’s Class AAA state title game against Peach County (14-0) at the Georgia Dome.

“I’m just ready to play,” said Johnson, who has 159 tackles, nine tackles for a loss and four sacks. “This is what we’ve worked for all season.”

Everyone knows that once Johnson (6-foot-3, 230 pounds) steps on the field, he leaves his Mr. Nice Guy personality in the locker room. Preparing for the opening kickoff, Johnson gets such an adrenaline rush that he instinctively breaks into a little dance as he charges the field, trying to keep his teammates just as pumped up for action.

And once he makes it into the opposing team’s backfield, the ball carrier will probably do anything within their power to avoid one of Johnson’s rib-rocking hits.

“He’s a great leader for our defense,” said senior linebacker Thomas Sprague, who leads the team with 187 tackles, including seven tackles for a loss. “He’s made so many big plays this season that it is hard to pick one that stands out above the rest.”

The big plays Johnson has made since stepping on the field as a freshman touch on all categories in which a defender can make an impact.

This year against Johnson High, he returned a ball stripped free from a pile of players and returned it for a touchdown of about 40 yards. He also delivered many key tackles last week against Flowery Branch in the state semifinals, including a sack on Falcons quarterback Connor Shaw.

As a sophomore, he impressed his coach, Bruce Miller, with an interception against Flowery Branch near the Gainesville end zone and returned it out to about the 50.

“A.J. is the ultimate competitor and doesn’t want to get beat at anything,” Miller said. “I’ve never seen a kid go like him on the field.”

“If I had any sense, I would have started him right away as a freshman.”

He didn’t start immediately, but Johnson showed quickly that he was cut out for playing varsity, even as a ninth grader. Miller remembers how his workhorse at middle linebacker first found his way onto the field.

It was the game against Pickens two years ago, and while the Red Elephants were leading 42-35, Miller and defensive coordinator Jim Pavao were not pleased with how they were playing on that side of the ball. Then Gainesville’s defensive coordinator decided to pull the trigger and see what the then-freshman Johnson could do.

To say he didn’t disappoint would be an understatement — Johnson made six consecutive tackles. His play at middle linebacker stopped the defensive bleeding and Gainesville went on to top Pickens 77-35.

The next week, Johnson was rewarded with a start against the Knights and finished with 17 tackles. He hasn’t left the starting lineup since.

Now, Johnson’s effort just highlights the performance of a tough linebacking crew for the Red Elephants, which also includes Sprague, Graham Simmons and Alberto Sanabria. Of course, with their gaudy tackle totals, Johnson and Sprague are the two that stick out among this foursome.

“They’re like Butch Cassidy and the Sundance Kid,” Miller said of Johnson’s and Sprague’s combination at linebacker. “They go great together.”

While the reference of Butch Cassidy and the Sundance Kid goes right over the heads of Sprague and Johnson, due to their young age, they still take it as a compliment.

“We just feed off of each other to get better,” Sprague said.

Of course, one more thing about Johnson that makes his coach smile is the fact that he’s guaranteed to be back in uniform for the Red Elephants for one more season after this weekend’s state championship game.

On a Gainesville team loaded with senior standouts, Johnson will be back in 2010 before heading off to the University of Tennessee to play football, where he is currently verbally committed.

“I’m just glad he can’t come out early,” said Miller, referring to a college players ability to turn pro after their junior season.

That in itself is enough to make any coach happy.