SANTA CLARA (AP) — As one of the smallest kids with five brothers growing up in Ohio, Chris Borland learned to protect himself at an early age.

During those intense backyard games, even playing fierce board games.

Each year he would ask his father if he could turn out for organized football, and every time he received the same answer: Not until high school.

Instead, Borland played soccer, basketball, tennis and some baseball to develop his athleticism and skills that are paying off for the rookie NFL linebacker with San Francisco.

“Being the younger brother was always huge, they’re dragging me along and I was always playing against older kids and my older brothers,” Borland said Thursday. “So, that helped me. I had to learn how to fight and play hard and everything because I was smaller than everybody.”

Any size disadvantage he has at 5 feet 11 and 248 pounds, Borland has overcome with the energy and spot-on instincts he brings to a 49ers defense in need of a morale boost from the newcomer.

Initially called upon to fill in while seven-time Pro Bowler Patrick Willis recovered from a toe injury, Borland’s job is suddenly more stable. Willis is done for the season with the troublesome left big toe, which will require surgery.

“You look at a guy like Borland, there’s no, ‘We’ll wait and get him ready,’” wide receiver Anquan Boldin said. “It’s, ‘You have to go now.’”

Borland hasn’t flinched. His numbers have been stellar — 35 tackles in the past two games, and a fumble recovery in overtime of last week’s win at New Orleans after Saints quarterback Drew Brees lost the ball.

“It’s more just being in the right place at the right time,” Borland said.

He certainly doesn’t look like a player whose football career began later than many. Borland, the second-youngest boy of the six who also have a sister, got plenty of informal football practice with his brothers, and he respects his dad’s decision.

“I just don’t think he thought youth football developed any skills. The biggest, fastest kids run around everybody and it’s not really a good example of football,” Borland said. “I think he had a good idea.”

And Borland isn’t about to start comparing the brothers’ athletic skills.

“You’re going to start an argument,” he said with a grin.

Borland has caught the attention of not only his teammates and coaches, but opponents who can’t help but notice what he has done in just three games since becoming a regular contributor.

Giants coach Tom Coughlin included. New York and Eli Manning must find a way to keep Borland in check when the 49ers play at the Meadowlands on Sunday.

“He’s talented, he’s smart, he puts himself in the right spot,” Coughlin said. “He is physical. He’s a good young linebacker.”

Limited in Wednesday’s practice with a shoulder issue, Borland was a full participant in Thursday’s workout.

Just 155-160 pounds when he began ninth grade, Borland found former Bears linebacker Brian Urlacher’s workouts online and used those to develop his own program, under the guidance of big brother, Joe.

“It was just intense, two hours straight lifting, nonstop,” he said. “It really helped me put on weight. I’m definitely stronger for it. ... I’m the biggest (in the family) but it wasn’t always the case. Everything was competitive, board games, backyard games, basketball.”

The 49ers selected Borland in the third round of this year’s draft out of Wisconsin, where he was an imposing pass-rusher.

He ended his Badgers career as the school’s sixth-leading tackler with 410, and was reliable in pass coverage. He had 15 forced fumbles, nine fumble recoveries, a blocked punt and 17 sacks.

As he made the jump to the next level — with the daunting task of filling the big void left by Willis’ injury — nothing has seemed too big so far for Borland, who is counted upon to get to the ball carrier and finish plays.

“Chris Borland didn’t prepare to be a great player in a week. He prepared since birth. That’s who he is, and I can see that even though I haven’t been around him except for a little bit of time now,” 49ers linebackers coach Jim Leavitt said.

“But you can see what this guy’s about. I can see why he was a tremendous player in college. ... He plays with everything he has. He has quick feet, he has a great nose for the ball, he anticipates extremely well.”

Notes: Boldin announced a $1 million endowment from him and his wife, Dionne, to the Anquan Boldin Foundation that will be dedicated to annual scholarships for high school graduates.