Gone is last year's sack leader for the San Francisco 49ers – defensive end Elvis Dumervil. While general manager John Lynch didn't completely shut the door on a potential return, it seems unlikely. You can certainly understand the 49ers wanting to focus on their younger talent, but the move made some wonder about the plan on defense.

Last year, the 49ers defense produced 161 quarterback hurries and 69 quarterback hits. The team's pass rush was good enough to rank 14th in the league in 2017 (per Pro Football Focus) when it came to pressure, yet it only brought down the quarterback 30 times (tied for 26th in the league). Defensive lineman DeForest Buckner led the team with 19 quarterback hits but was able to produce just three sacks.

What do these numbers mean? It feels like the 49ers are just an impactful pass rusher away from players like Buckner becoming dominant. The team re-signed defensive end Cassius Marsh this offseason and brought in Jeremiah Attaochu on a one-year deal. While a dominant pass rusher was seen as the 49ers' most significant need heading into the draft, round after round went by without the team addressing the position.

You can't always have a sack-producing machine like Joey Bosa or Von Miller fall into your lap during the draft. So the 49ers are taking a different approach until they can identify someone who can cause chaos at the Leo spot. Defensive coordinator Robert Saleh is hoping a group effort on defense can produce better results in pressuring opposing quarterbacks.

The 49ers did have one key offseason addition who Saleh believes will improve the defense's pass rush. Chris Kiffin, who is the son of Monte Kiffin and brother of Lane Kiffin, signed on as San Francisco's pass-rush specialist.

"A big thing I saw (from last year) was guys not necessarily rushing together," Kiffin recently told the Sacramento Bee. "You can't look at it as four individual rushers. It's really, you're rushing as one. If we can get that fixed, the pass rush improves."

Saleh is hoping Kiffin and defensive line coach Jeff Zgonina can work together to fix the 49ers' pass rush woes.

"Between him and Zgonina, they're doing a great job, both of them, they really are, with regards to just creating an identity of what we need to be on defense," Saleh told reporters on Wednesday. "When you look at the overall structure of our defense, there's no gray area in the way we teach. The run game is fit exactly the way we fit it. Our coverages, there's no gray area. There's no gray area in our alignments. There's a very defined role for everybody.

"When it got to pass rush, between Zgonina and coach Kiffin, they're doing a very, very good job eliminating all of the gray area in the pass rush. Creating a black and white picture so those guys understand exactly what job each person has, so they can learn how to play off of each other and they can rush as a unit. Between those guys, they're doing a great job early.

"I think the players are starting to understand exactly what it's supposed to look like. We're excited. We're excited to see what those guys are capable of once they learn how to rush as a unit."

The 49ers hope there is enough talent along the defensive line where coaching can produce better results. In the process, an impactful pass rusher may emerge. At least, that's what Saleh believes.

"You look at [Buckner], you look at Solomon (Thomas), there's enough talent on our D-line," Saleh said. "With football players, the difference between the top guy and the next guy is very little. We do think Buck is a dominant football player. We think Solomon's got great upside. Arik (Armstead) has still got tremendous upside, a ceiling that he hasn't even touched yet.

"Then you look at all of the Leos, between Eli (Harold), Dekoda (Watson), Pita (Taumoepenu), Cassius (Marsh), (Jeremiah) Attaochu, even Ronny Blair rushing on the inside. There's a lot of guys. I could name all of them. But, they're all fighting to show something so they can get opportunities to rush the passer this year. Sometimes when you're able to rush as a group, as a unit, especially with the way it's being designed, they can be very effective as a unit. They can.

"Not every team has a Joey Bosa or a Von Miller, where they can just take a complete game over. But, there's a lot of teams that have four really good rushers, and they are very effective rushing the passer, and that's what we're trying to build to be. Who knows, you might be surprised. There might be a star out of the bunch. I have a feeling there might be."