Doc's warnings go unheard

"[After Kevin Garnett's injury,] I heard a couple guys say we need guys to step up. I said, 'We don't need anyone to step up; we just need you to step into your role and do what you do.' I think what happens, guys do try to do more -- more than their ability -- and that's why you lose games." -- Celtics coach Doc Rivers before Friday's game against the Hornets

BOSTON -- Celtics coach Doc Rivers tried to warn his troops. It's almost as if he knew exactly how the script would play out three hours later. But despite repeated warnings to play within themselves, his players fell into the trap of trying to do too much down the stretch and fumbled away a winnable game, falling to the New Orleans Hornets 83-81 in a New Year's Eve matinee Friday at the TD Garden.

Fair or not, one play will stand out above the others.

After a feverish rally from a double-digit deficit put the Celtics up by seven midway through the fourth quarter, the Hornets rallied back and Trevor Ariza canned a crowd-silencing 3-pointer with 1:34 to play to break the final tie of the game.

Coming out of a timeout, Ray Allen missed a 3-pointer, but Jermaine O'Neal got an offensive rebound to keep the possession alive. Inexplicably, Glen Davis fired an off-the-mark 25-foot 3-pointer from the right wing with 13 seconds still showing on the shot clock.

New Orleans got the rebound, David West drilled a 19-foot jumper with less than a minute to play for a five-point cushion and the Celtics couldn't rally back.

Rivers barked at Davis for the ill-advised shot during a timeout after West's jumper, and Davis appeared to shout right back in the huddle. After the game, Rivers didn't hide his frustration when a reporter asked, in general, whether players had made mental miscues.

"Who are you talking about? I'm just curious; can you give me a name?" Rivers asked, before the Davis play was referenced.

"That's a very good observation. I'm going to let you just say that. It doesn't take a rocket scientist to see that," he said.

But Rivers also said it wasn't one play that did in the Celtics. No, there were plenty of miscues to go around. Davis, starting in place of Kevin Garnett, who was sitting out his first game since suffering a muscle sprain in Wednesday's loss to the Detroit Pistons, struggled as he finished with 4-of-14 shooting for eight points with four rebounds, two turnovers, a block and a steal over 35 minutes.

Not exactly on par with some of "The Ticket Stub" performances Davis turned in as Garnett's understudy in past seasons. That said, if his 3-point shot falls, he receives a hero's toast in this space. Instead, he landed in the doghouse on the final day of 2010 and departed the Garden quickly after Boston's third loss in four games.

Davis, who has three career 3-pointers to his credit, simply fell into a trap that Rivers had hoped his players wouldn't uncover on their own: Boston can't overcome all its injuries by playing hero basketball. It needs to win as a team.

And on a day Boston's starters struggled, it was the bench -- playing without Davis, its most consistent contributor this season -- that provided the Celtics' spark, thriving simply off energy of rarely used players like Von Wafer and Luke Harangody (as well as a gutsy 33-minute effort from veteran Jermaine O'Neal and another strong showing by Marquis Daniels).

It was a lineup of Daniels, O'Neal, Harangody, Allen and Nate Robinson that keyed a 16-0 run to open the fourth quarter, helping Boston turn an 11-point, third-quarter deficit into a 73-66 lead with 6:27 to play.

During the run, Boston leaned on its hallmarks: getting stops, and creating open looks by pushing the ball up the floor and finding the open man. The roof nearly blew off the Garden when Allen drilled consecutive 3-pointers to cap the spurt.

But with Davis and captain Paul Pierce returning to the floor with Boston clinging to a three-point cushion with 5:17 to go, the Celtics seemed to get away from what was working.

"We just didn't play consistently," said Pierce, who finished with 12 points on 5-of-10 shooting with seven rebounds, three assists, a block and a steal. But it was an ugly six in the turnover column that summed up his night, especially in a game in which Boston committed 19 turnovers (leading to 25 points).

Pierce also lost control of the ball on a potential final-possession play that left Allen hoisting a less-than-desirable final shot. (And even then, the asleep-at-the-wheel Celtics failed to foul, despite Chris Paul hauling in that rebound with 4.6 seconds remaining in a two-point game.)

"We probably should've kept Marquis in there for me late in the game," Pierce said. "When he was in the game, he had a very good stretch and we pushed the lead up. ... Maybe Paul Pierce has to do a better job in stepping up his game. I really didn't come to play today, evidently, when you look it up -- six turnovers, but we only lose by two."

Rivers stressed that he wasn't disappointed in his players' effort as a whole. Playing without what amounted to three starters -- Garnett, Rajon Rondo and Kendrick Perkins -- the Celtics still found a way to put themselves in a position to win a game they tried desperately to give away even before the final minutes. But there are no moral victories for this team, and it was the mental miscues that left Rivers agitated.

Rivers knows that with a healthy lineup, his team can get away with those sorts of mental hiccups. But it simply cannot overcome absences, sluggish play from the remaining starters and execution errors.

"I thought we had a little bit of hero ball," he said. "There's no doubt about that. And usually you lose when you do that. So we lost."

So despite Rivers' warnings, the Celtics learned the hard way. Hopefully it's a lesson they'll remember as they face the next several games with a depleted lineup.

Chris Forsberg is the Celtics reporter for ESPNBoston.com. Follow him on Twitter.