Anyone who evaluated the Raiders’ roster at the start of the 2015 season likely came to the same conclusion: the secondary is the weakness.

The first-half of the season did nothing to alter that opinion. The Raiders allowed an average of 314.6 passing yards per game, on pace to be the worst in franchise history.

But the group improved over the second half, particularly as waiver wire claim David Amerson came into his own. Oakland surrendered only 202.9 pass yards per game in the second half.

Suddenly, with an offseason spent fortifying the defense — and secondary in particularly — the group has a chance to be among the Raiders’ strengths.

Amerson, who was second in the NFL in passes defended at 25, is now the No. 2 cornerback after the signing of Sean Smith. Another free agent signee, Reggie Nelson, will handle one safety spot while first-round pick Karl Joseph will presumably hold down the other.

Count Ken Norton Jr. among those excited to see his new secondary.

“We see a real good backfield,” said Norton, who is entering his second season as a defensive coordinator. “We’re improving. We’re coaching better. They’re playing better. We want to make sure we add our rush, combined with our coverage. Those two are connected and they work together. They’re doing a fantastic job of understanding what we have. We have guys that can cover and we have guys that can rush. That should work out to be pretty good for us.”

Pass rusher Khalil Mack is also looking forward to seeing how a fortified secondary will help him and the rest of the front seven.

“It’s all about and coverage working together,” Mack said. “We want to be good enough for those guys as well.”

The additions in the backfield help provide depth at cornerback in addition to the talent infusion.

Suddenly, TJ Carrie goes from the Raiders’ No. 1 corner at the start of last season to perhaps their No. 3 or a guy viewed as versatile piece to bounce around at different secondary spots.

Then there’s DJ Hayden. He’s been working at the Raiders’ nickel back during OTAs and could have a chance to redefine himself in a less pressurized role now that he’s not counted on as a starter.

But Norton warned against assuming some seemingly well-defined roles are already set in stone.

“Roles are good, but at the same time, it’s competition,” Norton said. “There’s no spot that’s already given. It’s a matter of competing. Coming out here every day and working really hard to show what you have. We’ve surrounded all the players with really good football players. They can look to the side, look around the room, they see every day guys showing up, playing and competing. It’s important that the group sees their growth, how they’re improving every day, and knowing the tools that we have.”