The Washington Wizards have another opportunity to gain their first postseason berth since 2008.
The Celtics have dropped 10 straight on the road but haven't lost to the Wizards in more than three seasons with Rondo, who will face Washington for the first time in 2013-14 on Wednesday night.
Washington (38-36) failed to lock up a playoff spot Monday with a 100-94 loss at Charlotte. The Wizards were outscored 56-34 in the second half and need one more victory or a loss by New York to clinch.
"We really thought tonight was our night, but to have them come out and play the way that they played and beat us - that's tough," forward Al Harrington said.
Star guard John Wall made 4 of 16 shots for 10 points after he averaged 24.7 points over his previous three contests.
"I get the same looks that I get against most teams, I just didn't make 'em," Wall said. "I don't want it to happen but it's something I can deal with."
Now Wall will have to deal with being defended by Rondo for the first time. The Celtics guard doesn't play in back-to-back games following reconstructive knee surgery and sat out Monday's 94-80 loss at Chicago after he had 17 points and 11 assists Sunday in a 107-102 home loss to the Bulls.
Boston (23-51) has won six straight over Washington with Rondo in the lineup since an 85-83 road loss Jan. 22, 2011. The Celtics have taken eight of the last nine meetings, splitting two this season.
The Celtics have lost five straight and 10 of 11 overall as they try to avoid their longest road slide since a 12-game skid Jan. 7-Feb. 24, 2007. Ironically, they ended their last 10-game road losing streak in their last trip to Washington on Jan. 22.
Wall turned in his lone triple-double of the season in that contest with 28 points, 11 rebounds and 10 assists in a 113-111 overtime defeat. Jeff Green, a native of the Washington area, led all scorers with 39 points as the Celtics prevailed despite blowing an 18-point halftime lead.
Washington resembled two different teams Monday, shooting 58.5 percent in a 60-point first half and connecting on 36.8 percent of its shots after halftime.
"I don't know how much clearer it can be when we move the ball or when we don't," coach Randy Wittman said. "And we didn't in the second half, (we scored) 34 points because we were selfish to a point."
Brandon Bass and Jerryd Bayless each had 18 points Monday as Boston shot 40.3 percent. The Celtics shot 31.6 percent in the second half without guard Avery Bradley, who left with a sore Achilles.
"It really hurt us when he went out with that bad Achilles," coach Brad Stevens said. "That was a curve ball that we couldn't hit."
Bradley, second on the team with 14.2 points per game, is expected to play Wednesday.