OAKLAND – Richard Seymour saw this coming.

Wednesday, the Oakland defensive tackle and former All-Pro with New England said observers "would see" whatever problems the Raiders have when they hosted the Patriots.

Consider the Raiders' problems on defense highlighted again.

Oakland again couldn't stop the run or hold up in pass coverage. The defense missed chances to sack Tom Brady and failed too often on third down.

On a Sunday afternoon when their offense was ineffective at key points, the Raiders couldn't overcome their defensive shortcomings in a 31-19 loss to the Patriots at O.co Coliseum.

In the offseason, Oakland (2-2) made major financial commitments to the defense with big contracts for Seymour, linebacker Kamerion Wimbley, cornerback Stanford Routt and safety Michael Huff.

But the defense hasn't shown the dominance the Raiders wanted. Instead, the unit has struggled to stop the run and pass and been prone to penalties.

"The offense, they kept trying to plug away at it for us, and defensively, we just never could get off the field," Seymour said. "So we have to do a better job defensively, because the offense is carrying us right now, and it isn't good enough."

The offense wasn't blameless, though.

Jason Campbell threw two interceptions. The first came late in the second quarter when Oakland was on the New England 6-yard line. The ball slipped from Campbell's grasp as he tried to throw it out of the end zone, and Patrick Chung picked it off.

The Patriots (3-1) converted the turnover into a field goal to lead 17-10 at halftime.

"We have some things to keep working at," Raiders coach Hue Jackson said. "We have some things to shore up. We didn't play well in my opinion on either side of the ball."

The Raiders have struggled to stop the run since 2003, and the Patriots had no problem exploiting that weakness. New England ran for 183 yards, including 97 by rookie Stevan Ridley on only 10 carries.

Another ongoing issue is penalties, this time nine for 85 yards.

Seymour had two 15-yard penalties on the Patriots' opening drive, which concluded with a touchdown. The first was an unnecessary-roughness call for slinging Brady to the grass after a whistle had been blown for delay of game against New England. Seymour said he didn't hear the whistle.

Seymour also was flagged for making contact with running back BenJarvus Green-Ellis' face mask on a tackle.

"At the end of the day, that wasn't the story line," Seymour said. "The story line was we couldn't get off the field and there (were) too many penalties over the course of the game. You can't beat a good football team when you're beating yourself as well, so we have to play better."

On offense, that means scoring touchdowns when inside the opponent's 20-yard line. Two drives in the red zone ended with Sebastian Janikowski field goals of 28 and 26 yards.

Another penalty, an illegal block called on tackle Jared Veldheer, stunted the Raiders' opening drive on first and 10 from the Patriots' 13. That drive ended with Janikowski's 28-yard kick.

The inability to keep pace with the Patriots was disappointing for an offense that had topped 30 points the previous two games.

"We felt we were a really good offense, too, that could match, if it came to that," Campbell said. "One mistake like that (first interception) kind of throws you out of it. So it's a game that we'll definitely learn from."

Defensive tackle Tommy Kelly said the team couldn't ask for much more than Oakland's 504 yards of offense, but the defense didn't deliver.

"Every team makes mistakes, but we got to help them out," Kelly said of the defense. "When Jason throws a pick in the end zone, we can't let them go down and get three. Or seven. Or drive the whole field. We've got to get the ball back to the offense, and we didn't do that."

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