When the NFL season started more than four months ago, few people would have been surprised to see the Carolina Panthers and Pittsburgh Steelers in conference championship games.

They were much longer shots when the playoffs started – both were low-seeded wild-card teams.

But here they are in Sunday’s championship games: the Steelers in Denver and the Panthers in Seattle, each having won two games on the road. Pittsburgh was the sixth-seeded team in the AFC and beat Cincinnati and top-seeded Indianapolis; Carolina, No. 5 in the NFC, beat the New York Giants at the Meadowlands and then won in Chicago against the conference’s second-seeded team.

Both are legitimate challengers.

The Panthers represented the NFC in the Super Bowl two years ago, and this is Pittsburgh’s sixth trip in 12 years to the conference title game, including a loss at home last season to New England.

“The team has been so consistent over the last couple of years,” Denver coach Mike Shanahan says of the Steelers. “There’s a good reason why they were 15-1 last year, and there’s a good reason why they’re in the championship game this year – because they play physical.”

That might be the theme for both title games: physical (Pittsburgh and Carolina) against finesse (Denver and Seattle). But there’s more to it than that – both home teams can slug it out if needed.

Pittsburgh (13-5) at Denver (14-3)

Bill Cowher says he’d prefer his Steelers were at home rather than traveling for the third straight week.

Of course.

But the numbers say otherwise: Pittsburgh is 1-4 at home in conference title games during Cowher’s 14-season tenure, and lost the AFC championship game at Heinz Field 41-27 to New England last season.

But it’s not only the road that’s helping Pittsburgh, it’s Ben Roethlisberger, who as a rookie last season went 13-0 during the regular season but threw five interceptions in two home playoff games, nearly throwing away a narrow win over the Jets, then hurting his team against the Patriots.

Now, in his second playoff season, Roethlisberger has been doing the opposite: he has five TD passes, just one interception and a passer rating of 124.7 in wins over the Steelers and Colts.

So Pittsburgh is no longer just a team that passes occasionally to set up the running of Willie Parker outside and Jerome Bettis inside. In the 21-18 upset of Indianapolis, Roethlisberger came out throwing.

“To me, he has earned that trust,” Cowher said of his QB.

Jake Plummer, Denver’s quarterback, also has earned the trust of his coach.

Now in his third season with the Broncos after six years in Arizona, Plummer is finally playing a disciplined game with a career-low seven interceptions in a full 16-game season. It took that long to break the habits he had with the Cardinals, where he often felt he had to carry a bad team by himself.

Carolina (13-5) at Seattle (14-3)

The faces of this game are the teams’ offensive stars: Shaun Alexander of the Seahawks and Steve Smith of the Panthers.

Alexander, who led the league in rushing with 1,880 yards and scored an NFL-record 28 touchdowns, was the league’s MVP and offensive player of the year. Smith led the NFL with 103 receptions and had a career-best 218 yards on 12 receptions in the 29-21 win in Chicago that got them here.

But this goes beyond the two stars – yes, Alexander will play after leaving last week’s 20-10 win over Washington with a concussion.

It’s also a matchup of coaches with previous playoff success. Seattle’s Mike Holmgren won the 1997 Super Bowl with Green Bay and got back the next year, when the Packers lost to Denver. Carolina’s John Fox was defensive coordinator of the Giants when they lost in 2001, then got Carolina to the game two years ago, losing 32-29 to New England.

But their recent history is different. Until last Saturday’s win, Holmgren was 0-3 in the playoffs in his first six seasons in Seattle.