Poise and confidence weren't enough for Shaun King this time.

King's bid to become the first rookie quarterback to lead his team to the Super Bowl fell short Sunday, the victim of mistakes he said he'll dedicate his off-season to eliminating.

There were the two interceptions he threw in the NFC Championship game, a failure to score touchdowns on two trips inside the St. Louis 20, a costly delay of game penalty and two sacks that cost the Tampa Bay Buccaneers yardage and time on their last possession.

They all added up to an 11-6 loss to the St. Louis Rams, who were two-touchdown favorites but were unable to march up and down the field on the Bucs defense.

"This is the first time I've been on the side of a team not holding up its end, and I'm going to work this offseason to turn this thing around,'' said King, who completed 13 of 29 passes for 163 yards.

"I'm just thankful that I had an opportunity. I mean, how many rookies get to play for a championship? It's motivation to work hard and try to come back again.''

King's ability to remain calm under pressure was a big part of the Buccaneers' march to their first NFC Central title in 18 years, as well as a come-from-behind victory over Washington in last week's divisional playoff game.

But the 22-year-old played like a rookie much of Sunday. And while he did move his team within striking distance for a possible game-winning touchdown, his inexperience was too much for the Bucs to overcome.

The Rams' second interception, on a poorly thrown pass intended for Warrick Dunn, set up Kurt Warner's 30-yard touchdown pass to Ricky Proehl that put St. Louis ahead for good for 4:44 to go.

And, with the Bucs driving for a possible a game-winning touchdown, King said he might have serve his team better by throwing the ball away to avoid two of the five sacks recorded by the Rams defense.

"I obviously didn't play well enough for us to win, and that's how I judge my play,'' King said. "If we win, I feel we played well enough to win. If we lose, I feel I didn't play well enough for us to win.''

Just as they have done all season, the Bucs stayed close in spite of not being able to move the ball consistently on offense. King overcame a slow start to beat the Redskins, but he never really solved the Rams' swarming defense.

Tampa Bay settled for a field goal after Steve White's interception on the first play of the game gave the Bucs the ball at the St. Louis 20. King was unable to get his team into the end zone after his completion to Jacquez Green and a face mask penalty gave the Bucs a first down at the 12.

The Rams' game plan was to try to force King to beat them. Once Proehl's catch over Brian Kelly put St. Louis up, that's exactly what the rookie had to do.

"He came back for us four times, and we thought he had another one in him,'' defensive tackle Warren Sapp said, referring to the four come-from-behind victories King led down the stretch after replacing the injured Trent Dilfer.

King, 5-1 as a starter during the Bucs' run to the title game, moved Tampa Bay from its own 23 to the St. Louis 22 before a sack for a 12-yard loss took the steam out of the drive.

Tampa Bay chances were further damaged when an apparent 12-yard completion to Bert Emanuel — wiping out the yardage lost on the sack — was reversed when the play was reviewed after a booth replay.

Emanuel also the receiver in another costly play — or as it turned out, non-play.

The Bucs, leading 6-5, decided against punting of fourth-and-3 from the St. Louis 40 early in the fourth quarter. King flipped a short pass to Emanuel, who turned up the sideline and raced inside the Rams' 20.

But the officials ruled King didn't get the play off in time, and the Bucs were assessed a delay of game penalty and punted on the next play.

"I thought we got it off with one second left (on the play clock),'' King said. "The official made the call, and we'll have to live with it.''