Rough times just got rougher for the Boston Celtics who may be without Leandro Barbosa for the rest of the season.

Barbosa, who has seen his playing time increase since Rajon Rondo's season-ending torn right ACL injury, crumbled to the ground near the end of the third quarter with a left knee injury.

Limping towards the Celtics locker room after their 94-91 loss to Charlotte, Barbosa respectfully declined to speak with the media through team officials.

Celtics coach Doc Rivers said Barbosa will have an MRI performed on the knee tomorrow morning in Boston.

"It's not looking great," Rivers said of Barbosa's injury. "But we'll see."

The disappointment of seeing their season-best seven game winning streak come to an end was evident.

But the potential loss of Barbosa seemed to sting even more.

"We're falling like flies right now," said Boston's Kevin Garnett. "It's tough. It's just tough all the way around. You messing around with these guys and then all of a sudden you see a season-ender, season-ending injuries ... it's tough, man. We're grinding right now."

When asked later if he was pretty much being told that Barbosa's season is over, Garnett responded, "pretty much."

The injury was severe enough to where Barbosa could not get up on his own when it happened. Instead he had to be helped off the floor by teammate and fellow native of Brazil, Fab Melo, along with team trainer Ed Lacerte.

If Barbosa is out for the remainder of the season, he would be the third Celtic player to suffer a season-ending injury in less than a month.

Rajon Rondo suffered a torn right ACL injury Jan. 25 against the Atlanta Hawks. He was taken to a nearby hospital two days later for what was supposed to be precautionary X-rays.