Many began to question whether the Celtics should just pack it in the rest of the way and deal Paul Pierce or Kevin Garnett before the trade deadline, but they decided to stay the course - and the results have been almost hard to believe.
Coming off a remarkable comeback against one of the better teams in the Eastern Conference, Boston looks to improve to 14-4 since Rondo went down and win nine in a row at home for the first time since the end of the 2008-09 season when it meets the Hawks on Friday night.
Rondo tore his ACL in a 123-111 double-overtime loss in Atlanta on Jan. 25, Boston's sixth straight defeat as it blew a 27-point lead. The Celtics didn't know the severity of the injury until two days later during a home game against Miami, which they won 100-98 in double OT.
Following that victory, coach Doc Rivers said the team was down but would not give up.
"You can write the obituary," Rivers told reporters. "I'm not. You can go ahead, but I'm not. We won and so the way I look at it is we're going to stay in there."
Boston (33-27) has done more than just hang around. It led Philadelphia by 2 1/2 games for the eighth and final playoff berth in the East after beating the Heat, and it enters this matchup in seventh place with a 2 1/2-game advantage over eighth-place Milwaukee.
The Celtics were five games behind Brooklyn for fourth place but have pulled within 1 1/2 of the Nets for that spot. They trail the fifth-place Hawks (34-26) by one game.
Boston rallied from nine points down in the final 4:36 of Wednesday night's visit to Indiana, scoring the game's last 11 points to come away with an 83-81 win after Garnett found Jeff Green under the basket for a layup with 0.5 seconds remaining.
"We have found ways to win. The trust is there now," Green said after the Celtics' fourth straight victory. "Guys are giving what Doc wants. We are finding a way."
Boston found a way to win all three games at home in eliminating Atlanta in six games in the first round of last season's playoffs. Including the postseason, the Celtics have won 14 of 16 on their own court against the Hawks.
Road-weary Atlanta avoided a season high-tying fourth straight defeat Wednesday night with a 107-96 home win over the 76ers. The Hawks returned to Atlanta after splitting a six-game trip, and they're in the midst of playing 10 of 14 on the road.
Jeff Teague led the way against Philadelphia with 27 points and 11 assists, Al Horford added 21 points, 12 rebounds and six assists, and journeyman forward Anthony Tolliver came off the bench to score a season-high 21 points.
Tolliver went 7 of 10 from the field and hit 5 of 7 3-point attempts while also grabbing a season-best eight rebounds and blocking two shots.
"The starters played a lot of minutes on the road," said Tolliver, who came in averaging 3.4 points. "We knew that coming off the bench, we had to bring a lot of energy and help these starters get the win."
Boston won 89-81 in Atlanta in the first meeting this season Jan. 5. Rondo had a triple-double and Pierce chipped in with 26 points, nine rebounds and five assists.