TAMPA, Fla. -- When they got off to a 6-0 start this season, it seemed like the St. Louis Rams had a great chance to repeat as Super Bowl champs. But now at 9-6, with one week to go in the regular season, they haven't even clinched a playoff berth.

With a costly 38-35 loss to the Tampa Bay Buccaneers (10-5) on Monday night, the Rams saw the Bucs return to the postseason and handed the NFC West title to the New Orleans Saints (10-5). Even if the Rams beat the Saints in the regular-season finale and both teams finish 10-6, the Saints win the tiebreaker because New Orleans has a better conference record.

The Rams can clinch a playoff berth only if they win on Sunday and the Detroit Lions lose or tie against the Chicago Bears. Otherwise, the Rams become the eighth defending Super Bowl champion to miss the postseason.

All the blame for the struggling Rams, who have lost four of their last five games, goes to the defense. The Rams defense has given up so many yards and points that the offense needs to score almost every possession to win a game.

The Rams hired Bud Carson out of retirement in October to help improve the hapless defense. Carson, a respected defensive guru, played a major role as an assistant coach during the Pittsburgh Steelers' "Steel Curtain" era in the '70s.

But the defense has shown only a little improvement. Two weeks ago, the Rams gave up a season-low 16 points to the Panthers. They allowed 29 points to the Vikings last week, which might sound good since Minnesota has one of the most productive offenses in the game. On Monday, however, the Bucs' Warrick Dunn rushed for 145 yards and three scores while Keyshawn Johnson caught seven passes for 116 yards and two touchdowns.

Same old, same old.

If they are serious about making the playoffs, the Rams have to play much better defense at New Orleans on Sunday. And if they want a chance to win back-to-back Super Bowls, a great turnaround of the defense is necessary. Last year, the Rams made history by becoming the first Super Bowl champs who finished last the previous season. They can make more history if they advance to the playoffs this year. Since the NFL introduced a 16-game season in 1978, no team has ever made the playoffs when it allowed more than 412 points in the regular season. The Rams have already given up 450 points, only 10 points fewer than last season's Cincinnati Bengals, who ended with the worst defensive performance in NFL history.