The Celtics had won six of seven gamess before Tuesday’s 86-83 loss at Detroit. Delk, who turned 29 Tuesday, sat out his second straight game with a sprained left ankle.
Walker, who along with teammate Paul Pierce is a reserve for the Eastern Conference All-Stars, has missed the last four games with a sprained right knee.
Pierce had 30 points and 11 rebounds Tony Battie added 16 points for Boston, which shot just under 39 percent (28-of-72) in Tuesday’s loss. Pierce is averaging 33 points in the last four games.
The Celtics are 16-8 at the FleetCenter, where they have won six of the last seven meetings with the Pistons.
Detroit has alternated losses and wins in 10 games following a four-game winning streak that began the month.
The Pistons used a balanced attack in Tuesday win over Boston. Chauncey Billups scored 16 points and leading scorer Richard Hamilton added 14, but made just 5-of-17 shots. Corliss Williamson scored eight of his 12 points in the final 5:20, including the go-ahead free throws with 34 seconds left, and fellow reserve Mehmet Okur added 11 points.
Okur, a 6-11 rookie from Turkey, is averaging 5.0 points and 3.9 rebounds.