SAN DIEGO – Norv Turner, of all people, came up with the San Diego Chargers' hardest hit in weeks when he fired defensive coordinator Ted Cottrell on Tuesday.

In this Jan. 13, 2008 file photo, San Diego Chargers defensive coordinator Ted Cottrell looks on before an NFL divisional playoff football game against the Indianapolis Colts in Indianapolis. Cottrell was fired by the San Diego Chargers Tuesday Oct. 28, 2008, and replaced with inside linebackers coach Ron Rivera. (AP Photo/Jeff Roberson)

Cottrell was sacked by the head coach in large part because his defense couldn't get to opposing quarterbacks, the most glaring shortcoming for a unit that has had little spark since losing star outside linebacker Shawne Merriman to season-ending knee surgery after the first game.

Cottrell was replaced by inside linebackers coach Ron Rivera, a Super Bowl winner with the Chicago Bears in 1985. Rivera will have the bye week to figure out why the Chargers (3-5) have underperformed.

"Probably the things that we have needed to improve in are the same things that affected us in Week Two and so on," Turner said. "The same things have been an issue throughout the first eight games, at different times."

Any kind of week-to-week improvement "hasn't been there," Turner said. "We've been inconsistent and we've had the same things happen to us over and over in terms of teams throwing for a lot of yardage early in games, making big plays in the passing game and keeping the football."

Cottrell didn't return a call seeking comment. This is the third time he's been fired as a defensive coordinator. He was let go by the New York Jets after the 2003 season and by the Minnesota Vikings after Brad Childress took over as head coach following the 2005 season.

The Chargers have no sacks or interceptions in the last nine quarters. They are at or near the bottom of the league in several statistical categories, including 32nd in passing yards per game (265.1) and 23rd in points allowed per game (24.9).

Cottrell had become a popular target of fan ire as the Chargers lost three of their last four games, including a 37-32 loss to former teammate Drew Brees and the New Orleans Saints in London on Sunday.

That game was indicative of the Chargers' defensive shortcomings, with no pressure on the quarterback and a lot of passing yards. Brees threw for 339 yards and three touchdowns.

Cottrell was a personal favorite of general manager A.J. Smith going back to their days with the Buffalo Bills. Smith didn't return several calls seeking comment.

With the bye week coming up, Turner said he decided after Sunday's game that Cottrell had to go.

"Ultimately we had a lot of discussion after the game. Ultimately I've got to make a decision based on what's best on our football team and where we need to go and that was the decision I made," said Turner, who is 72-92-1 as an NFL head coach.

"We know what we have to do," the coach said. "We have to create more pressure on the quarterback, and obviously when we create pressure, not give up big plays."

After leading the NFL with 30 interceptions and 48 takeaways last year, the Chargers have only six pickoffs and 10 takeaways after eight games. After getting 42 sacks last year, they have 17 at the halfway point.

"Of course it's unfortunate but it is what it is," outside linebacker Shaun Phillips, who has a team-high 3 1/2 sacks, said in a text message. "I'm excited because it gives us some spark."

Turner, Cottrell and Rivera all joined the Chargers on Feb. 19, 2007. Rivera had interviewed for the job Turner got a week after Marty Schottenheimer was fired. Cottrell was given a two-year contract that day, and Rivera was hired hours later after the Bears said he wouldn't be back after a three-year run as their defensive coordinator.

"I think it's a great opportunity for myself personally and I think it's also an opportunity for us a team to do some things differently," Rivera said. "I think it's a good challenge."

Rivera "interacts well with players," Turner said. "He communicates extremely well. I believe he's experienced. I think his expectation level is very, very high, and I believe there's something to having done it and then having a feel for who you're playing and what you need to do to give your guys the best chance to succeed."

Rivera said he's been influenced by coaches with different philosophies and attitudes, including defensive coordinator Buddy Ryan when he played for the Bears.

"To come out and say I'm going to be aggressive all the time isn't a fair evaluation of my thought process," Rivera said. "I try to do it based on the situations."

Rivera said he still wants to be a head coach someday, "but right now my aspirations are to get this defense going, to get us to play to the way we did last year, and better. I feel very comfortable, very confident in these guys, that we will do the best we can to put them in position to give them the opportunity to make plays and help this football team win some games."