ALAMEDA, Calif. » Dan Williams has seen firsthand the impact a new coaching staff can have on a downtrodden franchise.

After spending time with Oakland coach Jack Del Rio and his staff, Williams believes they can have the same kind of impact on the Raiders that Bruce Arians had on his former team in Arizona.

"I’ve seen what has happened when a new head coach comes in and everyone buys in," Williams said Wednesday. "It doesn’t have to be a rebuilding year or we only won (three) games last year, let’s win five. We’ve got a new coach, we’ve got new people, a new system, let’s win right away instead of waiting two or three years or something."

Williams is one of several free agents the Raiders have added on the first two days of the league year with much of the focus so far on upgrading the front seven and the league’s least productive running game.

The Raiders also announced the signings of center Rodney Hudson, linebackers Malcolm Smith and Curtis Lofton, running back Roy Helu and blocking tight end Lee Smith.

"The No. 1 thing that attracted me to the Raiders is just the passion, the energy, just the positive feeling that we’re going to get this thing turned around," Lofton said. "Why not win now?"

The Raiders are coming off a 3-13 season and have gone 11 straight years without a playoff berth or winning record. They have just 11 wins the past three seasons but the new additions sense a positive vibe from Del Rio and his new staff.

Williams was part of a turnaround in Arizona where Arians took over a five-win team following the 2012 season and led them to double-digit win totals his first two years, including a playoff berth this season.

The Raiders will need plenty of help to do that but they have some building block pieces in linebacker Khalil Mack and quarterback Derek Carr — the team’s top two picks in last year’s draft. Williams said he was also enticed by talking to Super Bowl champions Justin Tuck and Charles Woodson.

"Those guys have won Super Bowls and reading their energy and dedication and how much they really want to turn things around in Oakland," Williams said. "Today, I just decided, I definitely want to be a part of this."

Williams is a stout run-stopper who played mostly nose tackle in Arizona’s 3-4 defense. He had the seventh best run stop percentage last season, according to Pro Football Focus. He played almost exclusively on first and second down but said the Raiders want him to "push the pocket" as a pass rusher.

The move to sign Hudson to a five-year deal worth $44.5 million means the Raiders will cut ties with incumbent center Stefen Wisniewski, who is also an unrestricted free agent.

Chiefs general manager John Dorsey said he was unwilling to match Oakland’s offer for Hudson.

Hudson was picked seven picks after Wisniewski in the 2011 draft at 55th overall. After playing mostly as a reserve as a rookie and being limited to three games his second year by a broken right leg, Hudson emerged as one of the top centers in the league the past two seasons. He started 31 of 32 games and helped lead one of the NFL’s best rushing attacks.

The Raiders finished last in the league in rushing last season but showed some promise late when Latavius Murray got a chance to be the starting halfback. Now they have also added a strong receiving back in Helu to the mix.

"There is a lot of positive energy," Hudson said. "These guys are excited, I’m excited. I met a few players, they’re very excited to get started. I think any time you have that good, positive energy around it is good."

Lofton and Malcolm Smith upgrade a linebacker group that includes Mack and Sio Moore and has a void in the middle. Lofton will fill the void at middle linebacker and Smith adds depth in case Moore does not recover from a hip injury or Mack is used as a defensive end.

Norton was Smith’s position coach in Seattle and was a factor in the decision to come to Oakland.

"It was a big part," he said. "It wasn’t the most important thing. It was definitely a part of it being familiar with him and his style."

AP Sports Writers Brett Martel and Dave Skretta contributed to this report.