By Gary Washburn, Globe Staff

CHARLOTTE -- The Celtics may have lost Leandro Barbosa for the season on Monday night with a left knee injury sustained late in the third quarter of the Celtics' 94-91 loss to the Charlotte Bobcats.

Barbosa grabbed a loose ball, passed it and then tumbled near the photographers area and stayed there as play continued on the other side of the court.

After Jeff Green fouled Brendan Haywood, Celtics players rushed to help Barbosa, who couldn't get up on his own. He was carried off the court by rookie center Fab Melo and head trainer Ed Lacerte without placing pressure on either leg. He will undergo an MRI on Tuesday but Celtics coach Doc Rivers said the injury didn't "look good" while Kevin Garnett said the players were told the injury is season ending.

“We got the news when we came in the locker room,” Garnett said. “It’s tough all the way around. You mesh with these guys and all of a sudden you see a season-ending injury. It’s tough. We’re grinding right now on top of a back-to-back emotional game.

“The blow of Barbosa is kind of the fog or the cloud that’s in the room right now.”

When asked if he was told Barbosa’s season was over, Garnett said, “Pretty much.”

Teammate Courtney Lee wasn’t so sure Barbosa was going to miss the season.

“We’re not sure what he has,” Lee said. “Hopefully he’ll be fine. Hopefully he’ll miss a couple of days and get back at it. We’re hoping it’s not too serious. I hope he’s OK though. He said he’s fine, so hopefully he just twisted something and needs ice and a couple of days of rest.”

He walked out of the Celtics locker room, noticeably limping on his left leg.

It is the third significant injury sustained in the past 16 games. Rajon Rondo tore his left anterior cruciate ligament on Jan. 25 at Atlanta while Jared Sullinger underwent season-ending back surgery on Feb. 1.

Barbosa was flourishing over the past few weeks and his 12-point fourth quarter helped the Celtics defeat the Toronto Raptors on Feb. 6 at Air Canada Centre. He finished with 3 points Monday on 1-for-6 shooting.

By Gary Washburn, Globe Staff

The New York Knicks did more than complain about two non-calls in the final minute of Game 1 against the Celtics. They sent tape of two controversial plays to the league office, according to an NBA source.

The Knicks had problem with Kevin Garnett's collision with Toney Douglas that preceded Ray Allen's game-winning 3-pointer with 11.6 seconds left. And they also pointed out to the NBA that Delonte West ran onto the court after Allen's 3-pointer to chest bump Allen and the Knicks wanted a technical foul for six players on the court.

According to the source, the NBA admitted that Garnett's trip of Douglas, who was chasing Allen, was a foul while West's running onto the court would have been ruled a delay of game.

By David Roher, Boston.com correspondent

Editor's note: David Roher is co-president of the Harvard Sports Analysis Collective, a student organization. See his other work at the group's web site. This is the first installment of a new series of blog posts about sports statistics and strategy.

If Kevin Garnett had taken a shot faster in the final minute vs. Tyson Chandler and the Mavericks, the outcome might have been different. (Associated Press)

The Celtics would prefer that every game ended like Sunday's: a strong performance resulted in not only a win, but also a stress-free last few minutes. But the disappointing end to Friday's Celtics-Mavericks game showed the importance of fine-grained tactics down the stretch. By not rushing the ball up the court with 38 seconds to go, Boston made a significant error that might have cost it the win.

To refresh your memory: it was a see-saw game, and the Celtics' six-point lead with around three minutes to play had dwindled to one point with less than a minute remaining. As the Mavericks looked for the go-ahead shot, Kevin Garnett intercepted Jason Kidd's pass. He safely dumped the ball off, and the five green jerseys meandered to their side of the court. More than 20 seconds after his steal, Garnett attempted a jumper. I'll leave out what happened next, not to spare you the pain, but to show that it's the process that matters here, not the result. It would have been nice if Garnett had made the basket. Duh. My issue is how long it took him to take the shot.

Readers might think that it's better to slow the pace when ahead late, and they're almost always right: longer possessions mean fewer possessions and fewer opportunities for the losing team to claw back. Factor in the Celtics' normally slow pace (91 possessions per game, 20th in the NBA) and it's an even stronger case. However, there’s another important factor here: the end of a quarter is a special scenario in which a team can gain an extra possession. When teams get the ball with 30-40 seconds to go in the first three quarters and get a shot off quickly, they deny their opponents a chance to run out the clock because they are almost guaranteeing themselves another possession.

The strategy is called the 2-for-1, and the statistically minded Celtics use it a lot in the first three quarters of a game (they'd used it at least once in their previous six outings). One of the reasons it works is that possessions ending in the first half of the shot clock usually result in more points than those that end in the second half. In a study my club did two years ago, we found the expected return from a possession was highest after an attempt just two seconds into it. This figure plateaued until about seven seconds into the possession, after which it gradually declined until the shot clock expired. The total decline was worth about .25 points, or about 22 points over an entire game. Think about it: as the clock winds down, players more often shoot because they need to get a shot off, not because they have a good chance of making the basket. As a result, a team isn't sacrificing much by shortening its first possession.

The problem with evaluating the 2-for-1 in the fourth quarter is that there are often more important strategic motives. When my club did a study of the tactic two years ago, my colleague Dan Yamins found that he had to exclude fourth-quarter data. After Garnett stole the ball on Friday, he and his teammates were probably thinking about those other factors that screwed up our study: if they could just make one more basket, they would be up 3 and have a great chance of winning.

They probably weren’t thinking about what would happen if they missed and the Mavericks followed with a basket, or even if the Celtics made a two-pointer and the Mavericks followed with a three. They'd want an extra possession, one with enough time to get a decent look. But by taking around 21 seconds in their possession, they were effectively dismissing these situations.

As it happened, Garnett missed and Jason Kidd hit a three with 2.5 seconds left. The Celtics were forced to attempt an inbounds-pass alley-oop that sailed straight out of bounds. The game was effectively over. Again, it's not the result that matters, but the result happens to provide a convenient example of the benefit of taking a faster shot: even in the worst possible case, the Celtics would have had enough time to send the game into overtime or win it with a three.

We do have to consider the impact on the best-case scenario: that the Celtics hit the initial shot. In this case, taking a quick shot admittedly increases the chance that the Mavericks would repeatedly foul the Celtics, extending the game as long as possible. However, the additional chance of fouling is slight and rarely works out for the fouling team. Recall all the times you've seen a team try to foul at the end of the game, and then count how many times it actually worked.

I'd guess that the lapse in judgment occurred on the floor and not the bench: the Celtics are one of the most statistically inclined teams in the NBA. It's pretty difficult to weigh your strategic goals while playing in a demanding game, especially when the right call, the 2-for-1, is usually only applicable in the first three quarters. Regardless, Celtics fans should hope that their team will be a bit hastier in future similar situations.