The Jaguars had one of the NFL's most consistent defenses between 2004 and 2007, stuffing running backs, harassing quarterbacks and holding opponents to 17 points or less in 36 of 64 games.
It was what Del Rio believed in, what he wanted, even what he demanded.
It just didn't last. With the Jaguars (4-4) heading into a bye week off a lopsided victory at Dallas, Del Rio reflected on his once-stout defense -- the unit that currently ranks 30th in the NFL and the one he's trying so desperately to turn around this season. He took blame for overrating personnel and missing badly on free agents and draft picks, and he vowed to return the defense to where it was a few years ago.
"Defensively, when we got here in '03, a lot of work went into establishing a mentality and a mindset of how we're going to do things," Del Rio said. "And our guys embraced it. We played some really stout defense for a number of years."
Del Rio mixed oversized tackles Marcus Stroud and John Henderson, speedy linebacker Mike Peterson and hard-hitting safety Donovin Darius with second-year linebacker Daryl Smith and third-year cornerback Rashean Mathis. It was a recipe for success.
The defense carried the franchise to the playoffs in 2005 and 2007, but that last postseason run was where things started to turn.
Brady completed 26 of 28 passes for 262 yards and three touchdowns in an AFC divisional game, taking advantage of a mostly nonexistent pass rush and picking apart Jacksonville's secondary.
In the aftermath of the 31-20 loss, Del Rio and then-personnel chief James "Shack" Harris decided to trade Stroud for two draft picks. They took those picks, packaged them with some of their own and moved up in the first and second rounds to select Florida defensive end Derrick Harvey and Auburn defensive end Quentin Groves.
It turned out to be Del Rio's worst move since putting a sharp ax and a tree stump in the middle of the locker room.
Harvey has six sacks in 40 career games and was finally benched last week. Groves was even less productive and was traded to Oakland in April.
Del Rio justified trading so many picks for two rookies by saying few draft choices would have made the roster.
"We probably underrated the number of players we had that were getting up in their years, that weren't going to continue playing for a long time," Del Rio said Wednesday. "I would say that's absolutely something we have to admit looking back, that to package that many picks and try and move, thinking you're that close, that's really not the sound way to do things.
"I think we gave into some of those thoughts, some of those feelings. To acknowledge that is just being honest."
"You never know how it's going to turn out," Mathis said. "You can go get a young guy in the draft or bring a guy here in free agency. We missed on both, in free agency and the draft. When you do that, it's going to take you a while to come back around."
The Jaguars overhauled their defense in 2009, then tweaked it again this offseason after finishing with a franchise-low 14 sacks.
With newcomers at nearly every position, the Jaguars have given up at least 26 points in eight games and are on pace to set franchise records in touchdowns, points and yards allowed. Nonetheless, Del Rio believes the defense is on the verge of playing better, just not quite ready to be like it was before.
"We have a good group of guys," he said. "We have an energetic group of coaches that are teachers, we have a group of guys that are willing to learn and they're unselfish. I like the way that were working at it, and I do feel that we will play much improved defense down the stretch here."
Copyright 2010 by The Associated Press