Boston ? Antoine Walker covered his head with a green towel, the same color on the 16 championship banners that hung overhead.

Perhaps he was thinking of the two free throws he missed with 1:30 left or his scoreless fourth quarter or his off-target 3-pointers. On the court, Paul Pierce’s frown told the story as the final seconds ticked away Friday night.

ex-Jayhawk Paul Pierce, center, was embraced by teammates Eric Williams, right, and Walter McCarty after the Celtics' come-from-behind victory against New Jersey in game three of the NBA Eastern Conference finals. That game proved one of the team's finest moments in a memorable season.

Two superstars who led the Boston Celtics all season let them down in the last game. Too bad they didn’t have more help.

But the Celtics exceeded expectations by making it to the Eastern Conference finals, beating defending conference champion Philadelphia and Central Division winner Detroit.

And they led the New Jersey Nets 2-1 before losing the last three games in their first trip to the conference finals in 14 years.

“This is just the start of something,” Pierce said after Friday night’s 96-88 loss. “We have nothing to hang our heads down for. We had a great year. This (disappointment) is nothing that is going to linger, not with me.”

The Celtics didn’t make the playoffs in his first three seasons. Walker was shut out in his first five.

And the team hadn’t made them in their last six. It took the departure of impatient Rick Pitino as coach and the arrival of imperturbable Jim O’Brien to change all that.

Pitino left last season with a 12-22 record and O’Brien led Boston to a 24-24 mark the rest of the way. With his coaching acumen and positive feedback, the Celtics soared this season to 49-33.

And they had a chance to reach the NBA Finals for the first time since 1987. But that team had three superstars Larry Bird, Kevin McHale and Robert Parish and a strong, reliable supporting cast.

This one had just two stars, Pierce and Walker, and a bunch of inconsistent, role players who specialized in one aspect of the game.

Tony Battie could rebound, Eric Williams could defend, but their offense was spotty. Tony Delk was a shooter, Walter McCarty was a leaper and Kenny Anderson was a playmaker with defensive shortcomings.

The Celtics relied too much on Pierce and Walker. They led the team in scoring in 94 of 98 games, including the playoffs. But with the Nets focusing on them Friday night, Walker had just 16 points and Pierce 14.

“Antoine and Paul, they played tremendous amounts of minutes throughout the whole year,” guard Erick Strickland said. “Their aggressiveness, it affects them in their legs and they’ve not been able to knock down those same shots they had earlier in the playoffs.”

The Celtics’ reliance on the 3-point shot helped most of the season as they hit 35.9 percent and made 699, second most in NBA history. But against the Nets, they sank just 27.3 percent of them and a mere 23.3 percent (7-for-30) in the decisive sixth game.

“I think the difference in this series was that the 3s that we had were on some really good penetrations and passes out that were wide open and didn’t fall,” O’Brien said. “We made no bones about the fact that we’re a team that is going to utilize the 3.”

In the final game, Walker was 1-for-9 and Pierce 2-for-7 on 3-pointers.

Boston’s team defense was solid until it met up with Jason Kidd, whose quick decisions and passes didn’t give the Celtics time to cover the recipient.

“Jason Kidd is off the chart as a player,” O’Brien said. “He is as good a point guard as I have ever seen.”

Some pretty good players watched from the stands Friday night Bill Russell, Bob Cousy, JoJo White and Chris Ford. All played on Celtics championship teams.

To get closer to that, the current team needs a physical power forward and another dependable scorer.

It may not need more playoff experience.

The Celtics went through various aspects of that this year winning the deciding fifth game against Philadelphia after blowing a 2-0 series lead, defeating Detroit four straight times after losing Game 1, and erasing a 21-point deficit after three quarters to beat New Jersey in Game 3.

Then they experienced something not as satisfying failure.

“We’re disappointed because we worked very hard,” McCarty said, “but this was a positive season, no matter what.”

Now the Celtics must learn from their mistakes to build on this season’s improvement.

“Me and Antoine are going to be here for the next 4-to-5 years, so the foundation is there for us,” Pierce said. “Nobody really expected us to get here. So I think this is just the beginning and, with time, we are going to get better.

“We have potential to be a championship team one day.”