Buffalo Bills linebacker Manny Lawson was blissfully unaware of his new team’s shortcomings.

“That is new knowledge to me,” he said Wednesday during his introductory news conference, when asked whether he had any preconceptions about signing with a team that’s failed to make the playoffs for 13 straight years. “I guess it’s good to know. I look at myself as: I’m coming here to change things.”

The Bills showed they believe Lawson can be a part of the franchise’s revival by dipping into the free-agent pool for the first time in 2013 and signing him to a four-year contract worth up to $12 million.

“This team really wanted me here,” said Lawson, who arrived in Buffalo on Tuesday night, the opening of free agency, “and that was just enough for me to come here.”

Lawson, 28, is a versatile defender who has experience the last two seasons in the Cincinnati Bengals’ base 4-3 scheme. But at 6-foot-5 and 240 pounds, he’s ideally suited to be a 3-4 strong-side linebacker, and he wanted to return to that role, which he played for San Francisco — the team that picked him 22nd overall in the 2006 NFL draft — at the start of his career.

His signing is an indication the Bills will line him up in that role in the new scheme installed by defensive coordinator Mike Pettine.

“I look at myself as also being a hybrid,” Lawson said, borrowing the word frequently used to describe Pettine’s new scheme. “I’m a defensive end in a linebacker’s body. I can drop into coverage. I can rush the passer. I think I fit well in this scheme in that I can bluff those same things, too. As far as creating mismatches for offenses, whether or not this guy’s going to do what he’s lined up to do right now based upon on previous film, I think I fit well in this scheme.”

Lawson started 25 games over the last two seasons for the Bengals, and is coming off a season in which he recorded 39 tackles, two sacks and one forced fumble. Lawson has 18 career sacks, but just six have come in the last three seasons.

The Bengals did not use him a lot as a pass rusher, something he hopes changes with the Bills.

“Definitely, I would like to rush the passer more,” he said. “And talking to Mike, with the packages that he has for us, I’ll get a chance to.”

In his last two years with the 49ers in a 3-4, Lawson played 67 percent of the defensive snaps. He played 47 percent for the Bengals in 2011, then just 34 percent last season.

“I think I pursue the ball well,” he said. “I can always use work in drop coverage and rush. I think I do those, if we had to do those on a grading scale, I give myself a C-plus.”

Lawson’s signing with the Bills will reunite him with college teammate Mario Williams. They played together on a defensive line at North Carolina State that also featured former Bills first-round draft pick John McCargo.

“It’s great to have somebody that you actually knew before the NFL came into our picture,” Lawson said. “We jawed back and forth and it’s good to know that’s still there and we actually do get a chance to, I guess you could say, rekindle our college lives.”

Lawson was also happy to sign a four-year deal after playing the last two seasons on one-year contracts.

“I still look at myself as being young, but you talk to a couple of the young guys, I’m now an ‘old head’ as they put it,” he said. “Just settling down, it’s a huge stress reliever.”

The hole at guard along the Bills’ offensive line is getting deeper by the day.

A day after the team lost left guard Andy Levitre, a player thought to be a candidate to replace him followed him out the door when Chad Rinehart signed a one-year contract with the San Diego Chargers.

Rinehart, 27, played in 27 games over the last three seasons as a key reserve along the line, making 17 starts. He played in just seven games and made two starts in 2012 before going on injured reserve because of an ankle injury he suffered in a Week Seven loss to Tennessee.

Rinehart, 6-foot-5 and 321 pounds, will be reunited with offensive line coach Joe D’Alessandris — who held the same job with the Bills last season — in San Diego.