NFL

Three battling to be Giants starting MLB

Two former high school rivals and a first-round flameout.

No, this isn’t a reality show — it’s the battle for the Giants’ middle linebacker spot, made vacant when Chase Blackburn signed in the offseason with the Panthers.

On the first day of organized team activities Wednesday, Mark Herzlich started, over fellow Pennsylvania product Dan Connor, who signed a one-year deal after one year with the Cowboys, and reclamation project Aaron Curry.

It’s a wide-open competition, coach Tom Coughlin said, repeatedly using the word “opportunity” to describe the situation. Of the three, the five-year veteran Connor has the most experience, the 27-year-old Curry the most talent and intrigue, while Herzlich is the most familiar with the Giants’ system.

Herzlich, in fact, was in the rotation at the position as a rookie, before suffering a high ankle sprain. The Giants picked up Blackburn when Herzlich went down and won the Super Bowl that year.

“It’s a big opportunity for me to step up, to play like I know I can play, and really lead the defense,” the third-year pro and cancer survivor said. “I knew my opportunity would come at some point and hopefully this year’s that time.”

Herzlich and Connor are now teammates, but they were adversaries several years ago, living 15 minutes from each other in tiny Pennsylvania towns. Herzlich joked Connor, a fullback back then who had 56 tackles for the Cowboys last season, introduced him to varsity football by running him over.

“I went to make a tackle and he put me right on my back,” he said.

Then there is Curry, a major disappointment with the Seahawks after he was taken fourth overall in the 2009 draft and given a six-year, $60 million contract including $34 million guaranteed. He was with the Raiders last year, but was cut in late November after spending all but two weeks of the season on the physically unable to perform list. He had arthroscopic surgery on his right knee in December. Curry said he’s healthy now and ready to make an impact, to shed the bust label.

“I just want to run around and hit things that are moving,” he said. “I hope to be able to uplift everything, do what’s asked of me, and do it at full speed.”

The 6-foot-2, 255-pound Curry said he wasn’t mature enough to succeed when he first got into the league, preoccupied with himself, “selfish” and “focused on my own desires.”

“Football wasn’t my top priority,” said Curry, who has 5 1/2 sacks and 190 tackles in his disappointing 48-game career.

He credits Seahawks linebackers coach Ken Norton Jr., the three-time Super Bowl champion, for waking him up. Norton, was “honest” and “harsh,” Curry said, wouldn’t let him cut corners and showed him “the right way” to approach his job.

“I’m willing to do whatever it takes that’s going to help the Giants be successful,” Curry said. “Now I’m more about finding a way to put out a lot of effort, a lot of energy, and cause havoc.”

zbraziller@nypost.com