ALAMEDA — Hey, Reggie Nelson, how’s that Raiders defense looking?\

“Ask me that next week,” the 11th-year safety said. “I’ll probably have an answer for you next week.”

Until then? So many questions.

The Raiders open the season Sunday against the Tennessee Titans amid skepticism that they are capable of slowing anyone down, let alone stopping them.

Oakland ranked 26th in total defense a year ago (24th against the pass, 23rd against the rush).

Most damning of all: The Raiders gave up 61 passing plays of 20 yards or more, the most in the NFL. They also tied for the NFL-worst by allowing 16 passing plays of 40 yards or more.

But after surrendering all those big plays, the Raiders made only small changes. They find out starting Sunday if it will be enough.

“I’m more confident than a lot of other people,” head coach Jack Del Rio said. “But, again, you get a chance to prove it. I think talk is cheap.

“There’s no sense in really trying to proclaim anything. I think we put in a lot of good, hard work. We have a good group of guys that are really looking forward to the challenges that are in front of us.”

After surrendering 24.1 points per game last season, the Raiders front office spent their off-season loading up on … more offense. Their notable acquisitions include receiver Cordarrelle Patterson, running back Marshawn Lynch, tight end Jared Cook and right tackle Marshall Newhouse.

Their lone notable defensive free agent signing — linebacker Jelani Jenkins — failed to impress during the preseason and failed to make the roster. Like our Oakland Raiders Facebook page for more Raiders news, commentary and conversation.

General Manager Reggie McKenzie did use his top three picks on defensive players, but there will be limited Week 1 impact. First-rounder Gareon Conley was limited by a shin injury during training camp and expected to spend Sunday on the inactive list.

Obi Melifonwu, a second-round safety underwent knee surgery and will spend at least half the season on injured reserve. Third-round pick Eddie Vanderdoes, a defensive tackle from UCLA, is in line to start against the Titans.

How in the world will the Raiders defense dramatically improve? The biggest buzzword during camp was “communication.”

The Raiders added John Pagano to the staff as the assistant head coach / defense. Pagano, a former defensive coodinator for the San Diego Chargers, will work alongside incumbent Ken Norton Jr. to try to fix what’s ailing them.

Nelson said it’s making a difference.

“(Pagano) has been a tremendous help with us,” he said. “Just his knowledge of the game, another defensive coordinator in the room. He’s been doing a great job getting us on the same page — from the linebackers to the cornerbacks to the safeties. That’s a tremendous step up with him helping out with Norton and Coach Jack.”

Cornerback David Amerson said: “It’s just a different beat. … A lot of the same guys came back, so you’re familiar with playing with your guys. I feel like we’re going to shock a lot of people.”

Bruce Irvin knows was a good defense is supposed to look like. The strong-side linebacker spent his first four seasons on Seattle Seahawks units that led the NFL in scoring defense each year. For complete Oakland Raiders coverage follow us on Flipboard.

Irvin, who turns 30 on Nov. 1, looked around Thursday and realized he was something of antique the Raiders locker room.

“It’s good in a lot of ways. Those guys look up to me, he joked. “But they also think I’m an old guy, that’s the bad thing.”

The youth around him is the biggest reason Irvin thinks the Raiders defense will be better this year. He said that Marquel Lee, a fifth-round pick out of Wake Forest, has quickly emerged as a confident leader as the team’s MIKE linebacker spot.

Irvin also predicted bigger days ahead for defensive linemen Mario Edwards Jr., Denico Autry, Treyvon Hester and Eddie Vanderdoes.

“Denico’s had a great camp, looked good. I’m excited for all those guys,” Irvin said. “I think we’ve got a great young group.”

This marks the third season in a row that the Raiders have played at Tennessee. They won the previous two largely behind the defense. They won 17-10 there last year (holding Marcus Mariota to a 46.8 passer rating) and 24-21 in 2015 (Nate Allen intercepted Mariota with 43 seconds left to save the game).

Norton was asked Thursday whether there was an urgency to throw in a few more schematic wrinkles this season considering he has mostly the same personnel from a year ago.

“The urgency is to coach better. The urgency is that the players must eliminate mistakes,” Norton said. “We’re all working together. We’re very talented. We’re working really hard. We’re excited about our challenge.”