The San Francisco 49ers need to improve on defense. And that improvement starts with the pass rush.

The Niners had 28 sacks last season, 29th in the league. They had a mere 13 sacks when sending four or fewer pass-rushers, which was tied for the second fewest in the NFL.

Defensive coordinator Jim O'Neil, who spent the last two seasons in the same role for the Cleveland Browns, says his 3-4 scheme should afford more chances to get to the quarterback.

"We’ve been able to, at times, rush three over the years and get pressure on the quarterback," O'Neil said Wednesday in his first news conference with the 49ers. "We’ve been able to rush four at times and get great pressure on the quarterback. And then, when we haven’t had a great pass rush, that’s when you pressure and you blitz more. So, we’re going to find ways to get after the quarterback, whether it’s three, four, five, six, seven guys if we have to, because if you let quarterbacks be comfortable in the pocket, it’s hard to win."

The 49ers found that out last season, going 5-11 and finishing last in the NFC West. O'Neil said he is working with the defense on three attributes to help them find success.

"The first one was being relentless. We want to coach guys how to play football, not how hard to play," he said. "The next one was accountability. Everybody has a job, get your job done. The guys that consistently do that will be the guys that will play for us. And, the last one was being productive. There’s a lot of guys that are scared to make plays. We want to find guys that trust their technique and are confident enough to go make plays in this league, because that’s what it’s all about.”

O'Neil said coach Chip Kelly has been sitting in on defensive meetings.

“He’s very involved. I want to build this thing to complement coach’s offense. So, the best teams play complementary football,” O'Neil said.

“Obviously (our offense is) going to go fast. So teams, for us, are probably going to try and run the ball a little bit more to wind the clock and keep their defense off the field. So, it probably makes offensives a little more predictable if our offense has it rolling.”