JACKSONVILLE — You can't blame the Jaguars' defense for being confident.First there was a division title, finishing second in the NFL in points and yards allowed, then holding Buffalo to three points last week in Jacksonville's first playoff game in a decade.Now they go to the stadium where they played perhaps their most impressive game of the season, a dominating 30-9 win at Pittsburgh in October."We hit them in the mouth," said defensive end Dante Fowler, the former Lakewood High and Gators star, who had a sack against the Steelers. "We know they're going to come with their A-game. We're going to get ready to go up there and have a battle."Ben Roethlisberger threw five interceptions for the first and only time in his 220 career games in the NFL. The Steelers went 13-3 and took their other two losses by six and three points, the latter against the Patriots.But Jacksonville owned that day — linebacker Telvin Smith and safety Barry Church each returned interceptions for touchdowns, and rookie running back Leonard Fournette punctuated the win with a 90-yard touchdown run with two minutes to play, giving him 181 for the day.The last time the Jaguars made the playoffs, in 2007, they eliminated the Steelers, intercepted Roethlisberger three times in a 31-29 win, thanks to a field goal with 37 seconds left.Most of the Jaguars' defense wasn't around then — the core includes Fowler (8.0 sacks) in his third season and three second-year stars: corner Jalen Ramsey (four INTs), defensive end Yannick Ngakoue (12 sacks) and linebacker Myles Jack (90 tackles).And while they're all making their playoff debuts this month, Jacksonville has spent heavily in free agency, adding top-tier veterans with postseason experience. Defensive end Malik Jackson is playing in his 11th career playoff game, having scored a touchdown in the Broncos' Super Bowl win two years ago against Carolina, but appreciates what this means to his new team."We're one of eight left. That's a huge accomplishment," Jackson said. "Let them enjoy it, but then we come in and go to the next task at hand and that's a team that got a bye week. They're going to be healthy and ready to go, and we have to be ready to go. We have to let these guys have fun, but understand we have bigger fish to fry."Defensive end Calais Campbell is also playing in his 11th playoff game, and racked up 14.5 sacks as a huge addition to Jacksonville's defense. He played in a Super Bowl in Tampa as a rookie with Arizona nine years ago, and now leads a unit trying to make an improbable trip to another."This is the hardest I've ever worked in my whole career," Campbell said. "This team is incredible, and we have so many playmakers, different guys who love the game and play the right way."When the Jaguars won in Pittsburgh in October, quarterback Blake Bortles threw for just 95 yards on 14 attempts. In last week's win against Buffalo, Jacksonville again won without any real passing game, getting only 87 yards from Bortles, who rushed for a career-best 89 instead.His defense isn't likely to get five interceptions this time around, and Bortles knows the offense will need to step up if the Jaguars want to continue their postseason run beyond Pittsburgh."We've got to find ways to make moves, start faster and make that consistent throughout the game," Bortles said. "There's a lot of stuff we'll have to correct and get rolling. … Going into the game, there's no secret recipe on how to win. You've got to score one more point than they score, regardless of if it's 50 or 3. You've got to find a way to outscore them."