NFL

BOLEY, BERNARD MEAN GIANT UPGRADE ON DEFENSE

On the second day of NFL free agency, the Giants believe they greatly enhanced their defense with the additions of linebacker Michael Boley and defensive tackle Rocky Bernard.

Boley will move into the starting lineup – the Giants didn’t come up with a five-year, $25 million contract and guarantee $11 million for him to wait in the wings. Coach Tom Coughlin said Boley will move to the weak side after he spent his first four years with the Falcons on the strong side.

Instantly, Boley becomes the best linebacker in coverage on the roster, but the Giants expect more from him.

“We’ve addressed a position of need,” Coughlin said. “He’s a guy that has not been used a lot in blitzing or pressure, because they’ve used him in coverage. He can cover, but we think we can take advantage of his speed. He is fast and athletic. I think we can call upon him to be involved in coverage and to be a pressure linebacker.”

Bernard, who will turn 30 on April 19, arrives after seven years with the Seahawks to fit in a defensive tackle rotation along with starters Fred Robbins and Barry Cofield.

“I thought a change of scenery would be good,” Bernard said.

The Giants can use Boley’s speed on special teams and won’t have to take him off the field on third down. They insist Boley, who did not miss a game in four years, is nearly 15 pounds heavier than his listed weight of 223.

“Michael is a three-down player who is durable and athletic,” general manager Jerry Reese said. “Michael will immediately upgrade our speed on defense.”

Boley, 26, appeared to be a rising star in 2007 when he had a career-best season with 110 tackles, three sacks, two interceptions and three forced fumbles. He tailed off last year and late in the season was benched in favor of Coy Wire as the Falcons went to a less aggressive system under Mike Smith that did not suit Boley’s skills.

As a run-and-hit linebacker, the Giants hope Boley provides what thus far Gerris Wilkinson has not. Reese likes Wilkinson’s athletic ability, but the past two seasons he has been unable to stay healthy and on the field. Wilkinson’s roster spot could definitely be in danger, with Bryan Kehl coming off a promising rookie year.

“I’m excited,” Boley said. “It’s a new beginning. This is a great team and a great organization. I’m looking forward to getting started here.”

The Giants aren’t done. Cowboys defensive end Chris Canty arrived late in the afternoon and will conclude his visit today. If the Giants don’t sign him, Canty will head for Seattle.

Canty, at 26 years old, should command at least as much as Antonio Smith, the former Cardinals defensive end who signed a five-year, $35 million contract ($12.5 million guaranteed) with the Texans.

As for the Giants’ unrestricted free agents, Derrick Ward visited with the Bengals and is headed next to Denver, then St. Louis. The market may be slower than Ward anticipated. James Butler, a starting safety the past two years, made the obvious visit to St. Louis, where his former defensive coordinator, Steve Spagnuolo, is the new head coach of the Rams. Butler could be headed to Cleveland next.

paul.schwartz@nypost.com