When the final whistle blew at the TD Garden on Jan. 27, all star forward Paul Pierce, the rest of the Boston Celtics organization, and fans across New England were in sheer ecstasy. The Celtics had just upset the defending champion Miami Heat 100-98 in a double overtime thriller.

Kevin Garnett and the other Celtic players smiled, joked, and hugged each other in delight. However, head coach Doc Rivers did not smile. He did not laugh. He did not hug his players. Something was wrong.

After the game, Rivers alerted his players that four-time all star Rajon Rondo had torn his ACL in his right knee and that he would miss the remainder of the season.

“I knew before the game, but I didn’t tell anyone. Obviously it was pretty emotional.”

Celtics star forward Kevin Garnett, one of Rondo’s closest friends on the team, did not take his teammates injury well.

“It was a big blow to everybody in here, me included,” Garnett said. “Man, that hurt. It’s tough. We had a tough game, came in, and he told the whole team in the locker room. It’s tough, tough on everybody.”

Before the injury, Rondo was averaging 13.7 points, 11.1 assists, and 5.6 rebounds in 38 games this season.

His injury was certain to exhaust any playoff hopes the team had. How could the mediocre Celtics possibly subsist without the NBA leader in assists and triple-doubles and one of the best rebounding guards in the league?

But not only have the Celtics survived, they have flourished. That includes impressive wins over the Heat, Clippers, and Lakers.

“We’re not going to make excuses, who’s out there, who’s not out there,” Pierce said. “We’ve got a lot of talent in this room. The rest of the teams are going to take it how they’re going to take it. We’re fine with flying under the radar, no expectations and everybody doesn’t expect anything of us, but we’re going to keep moving along like we’re moving and trying to get better.”

Since Rondo’s injury, guards Courtney Lee, Jason Terry and Avery Bradley have stepped up to fill the role of their two star guards. The Celtics have also acquired Jordan Crawford from the Washington Wizards at the trade deadline.

Crawford should undoubtedly help the injury-laden Celtics. He is averaging 13.1 points, 3.6 assists and 3.1 rebounds per game.

Nonetheless, the Celtics sit at the seven seed in the Eastern Conference standings with a 29-26 record. Were the playoffs to end today, Boston would face the Indiana Pacers in a favorable first round match up.

Given the adversity this team has overcome this season, anything seems possible.