They certainly could have used him in last week's last-second loss to the Philadelphia 76ers.
Boston tries to avenge that defeat when it visits the 76ers on Wednesday night.
The Celtics (16-33) had dropped four in a row and 19 of 22 before beating Orlando 96-89 on Sunday. The game was Rondo's best in seven contests since returning from a torn ACL as he scored 19 points, recorded six of his 10 assists in the fourth quarter, grabbed six rebounds and had three steals.
"I think we execute a little crisper," coach Brad Stevens said of his team's ball movement since Rondo's return. "I think that obviously the ball's in one person's hands a little bit longer, but that's because he's your playmaker and leader.
"The ball seems to have found the right guys a lot, especially today, and I think that's more so guys getting used to playing with one another."
While Rondo shot 27.9 percent as the Celtics lost each of his first six games back, he went 9 of 11 from the field against the Magic. He is a career 47.9 percent shooter.
"That's one of those things that when you don't play for a year, that shot's probably a little bit rusty," Stevens said. "But now that he's seven games back, he's a very, very good shooter who has put in more time to be a good shooter; better than his statistics in the past would say. I feel really good about him pulling up and making those shots."
The Celtics surely missed Rondo in a 95-94 defeat to Philadelphia (15-34) last Wednesday. The four-time All-Star was held out after playing 27 minutes in a 114-88 loss at New York the previous night.
Sullinger had 24 points and 17 boards as the Celtics held a 59-40 edge on the glass, but the 76ers held Boston to 36.8 percent from the field and won on Evan Turner's fadeaway jumper as time expired.
Nothing has gone Philadelphia's way since that win, dropping its last three games by an average of 16.3 points. The 76ers shot 52.1 percent but matched a season high with 26 turnovers in Monday's 108-102 loss at Brooklyn.
Michael Carter-Williams had 21 points, but he and Spencer Hawes both committed six turnovers. Tony Wroten and Turner had four apiece.
"We just had a lot of unforced turnovers," forward Thaddeus Young told the team's official website. "Just shooting shots over guys when we could have been kicking it back out when we get into those situations, we have to learn to just back the ball out or turn around and kick it back out to guys."
The 76ers now return home, where they have lost five straight and 11 of 13. Philadelphia hasn't suffered six consecutive home losses since a franchise-worst 12-game skid in 1996-97.
Boston, which has dropped 11 of 12 on the road, is 1-4 in its last five visits to Philadelphia.
Rondo is averaging 15.4 assists in his past five matchups with the 76ers.