BOSTON — The Boston Celtics came back from California, not champions and not whole.

They returned from Los Angeles following a long day of travel without the Larry O'Brien trophy and without Ray Allen, who stayed behind to attend to his ill son.

Unable to put the finishing touches on the Los Angeles Lakers and wrap up their first championship since 1986, the Celtics, the NBA's best team since November, flew back across three time zones Monday for a Game 6 they were hoping they wouldn't have to play.

But injuries, another big first-half deficit and a sub-par performance by Kevin Garnett cost them in Game 5, a 103-98 loss in the season's final game at Staples Center.

"Not what we wanted," coach Doc Rivers said of the team's stay near the Pacific Ocean. "We wanted two more (wins). Obviously, the blanket was that we get to go home, but we really believed that we could win one of these games. We won one and we'll take it, but that's obviously not what we want."

The Celtics weren't at full strength for Game 5, missing center Kendrick Perkins with a shoulder injury. Whether he'll play in Game 6 will be a game-time decision, but Boston expects to have Allen available.

The shooting star left the arena immediately following Sunday's game because of a "health issue" with his toddler son, Walker, who underwent medical tests Sunday and Monday. Allen was still at the hospital when the rest of the Celtics arrived in Boston at about 10:30 p.m. EDT Monday, team spokesman Jeff Twiss told The Associated Press.

Allen planned to take an overnight flight so he could play Tuesday night, according to Twiss.

Earlier, the Celtics waited at LA International Airport for their flight, which was delayed by mechanical problems. Another plane was brought in for the trip.

Their title was postponed, too.

On Sunday, the Celtics, who once trailed by 19 points, were moments away from an awards ceremony that's now on hold. Instead of hoisting a trophy and spraying champagne the Celtics returned to New England with more work to do.

Despite the loss, they feel good about their chances of winning a 17th title — on the 17th.

"We're one up, with two games to go at home," said Paul Pierce, who scored 38 in Game 5. "It still feels like we have the advantage, and I do feel like we're the better team."

So the 11th installment of Celtics vs. Lakers, the league's signature rivalry and one of the best in pro sports, has at least one more 48-minute episode.

After a 21-year gap between finals meetings, these teams aren't ready to part company.

Why would they?

Now five games old, this series has had plenty of drama (Pierce's return from a Game 1 knee injury), history (Boston's finals record 24-point comeback in Game 4), surprises (Leon Powe's emergence as a Game 2 star) and even a little scandal as former referee Tim Donaghy's allegations of fixed playoff games has hung over the finals.

The Lakers are trying to become the first team in finals history to overcome a 3-1 deficit to win a title.

Kobe Bryant and his teammates staved off elimination Sunday by getting more physical with the Celtics, who Tuesday night will play their 26th game of this postseason — a record — and could be wearing down physically.

Bryant has yet to have a blowout, 40- to 50-point game and doesn't think he needs one for the Lakers to win their title.

"Could I force myself to get 40? Yeah. But is that better for our ballclub? No," Bryant said. "We've got guys open, I'm going to move the ball."

In Game 5, Los Angeles center Pau Gasol shed his "soft" label for a night and scored 19 points with 13 rebounds.