Though they're sitting atop the Southwest Division, the banged-up San Antonio Spurs have fallen off their earlier pace over the last three-plus weeks.
They've played well against Boston of late, but the Celtics are starting to hold their own.
The visiting Spurs go for a fifth consecutive win in the series as the teams play their final game before the All-Star break Wednesday night.
San Antonio (37-15) is looking to get back on track after falling 109-100 at Detroit on Monday. Reserve Marco Belinelli had 20 points but was the only Spur to score more than 12 for San Antonio, 6-7 in its last 13.
The Spurs gave up 59 points in the first two quarters and trailed by as many as 23 against the Pistons, who were playing their first game under interim coach John Loyer.
"We lost the game because we probably played the worst defense we've played all season, especially in the first half," coach Gregg Popovich said. "We didn't bring it mentally or physically."
San Antonio continues to play without Manu Ginobili and Kawhi Leonard, and Tiago Splitter missed his second straight game with a shin contusion. Danny Green, who recently returned from a broken hand, is expected to be OK after spraining his knuckle Monday.
"We're playing with a lot of different guys right now, we're missing a lot of our key guys," Tim Duncan said. "(We'll) try to finish this road trip strong and get a win in Boston and see if we can get healthy over the break."
The Spurs have allowed an average of 91.8 points in taking four straight from the Celtics, including a 104-93 victory Nov. 20. Tony Parker led six Spurs in double figures with 19 points as San Antonio scored 25 off 17 Boston turnovers.
The Celtics (19-34) have followed a 3-19 stretch by winning four of five. Jeff Green led the way with 29 points in Monday's 102-86 victory at Milwaukee.
"There are a lot of good things going on out there right now. There are guys stepping up," guard Jerryd Bayless said. "We have to continue to get it all the way around from everybody. When that continues to flow and everybody is playing well together we are a pretty good team."
Green, averaging a team-leading 16.6 points, has scored 25.0 per game over the last four.
"I am confident in every shot I put up," Green said. "Whenever it leaves my hand, I am confident that it will go in. ... That is my game, driving to the rim."
Jared Sullinger extended his career-best streak of double-doubles to six with 13 points and 10 rebounds. Rookie Kelly Olynyk added 14 and 11 off the bench.
"We talked about this before, Kelly and Jared's ability to pass, play and score," Stevens said. "It's great to have them in because they make so many basketball plays and you can run so much through them. They can handle the ball and they can do all kinds of things."
Sullinger is averaging 19.8 points and 12.8 boards during his run. He had 19 and 17 on Nov. 20.
All-Star point guard Rajon Rondo could return after sitting out Monday's game, the second of a back-to-back. He's averaged 14.0 points, 11.0 assists, 7.7 rebounds and 61.3 percent shooting in three games this month.
Fellow guard Avery Bradley's status is uncertain due to a sprained ankle.