Bench must stand on its own two feet

Coach Doc Rivers was able to use his bench extensively, but even then he didn’t as much as he should have. In the second quarter, Paul Pierce collided with Trenton Hassell and the two banged knees, leaving Pierce limping back to the bench.

“I’m fine,’’ Pierce said. “I got hit in the knee a couple of times but I am OK.’’

That didn’t deter Rivers from using Pierce for nearly 11 minutes of the third quarter - after the Celtics built a 36-point halftime lead - to pile up his total to 28 minutes on a night when Boston was never threatened. Tonight’s game against Chicago concludes a stretch of six games in nine days, and the Celtics are exhausted, especially the veterans.

After missing five games with a right knee infection, Pierce logged 43, 41, 34, and 42 minutes before his 28 last night. Rivers has to figure out how to give his guys more rest against bad teams and allow his bench players to gain confidence and experience with quality minutes.

“It was good for me to play limited minutes tonight,’’ Pierce said. “I think [Monday] I played like, over 40 minutes, so hopefully these young guys can come in and give us sort of a breather while we’re hurting, man. It’s going to be big until we get healthy.’’

J.R. Giddens, Shelden Williams, and Walker are not going to help down the stretch by osmosis. They need to play, and against a team that essentially didn’t show up until the second half, this would have been the perfect opportunity.

When the second unit did get out there, they looked like one of those pee-wee teams that plays at halftime at TD Garden. The only thing missing was coach Willie Maye’s play-by-play. Because they don’t play together much, they looked confused, unsure, befuddled.

With Rasheed Wallace out for another few days with a foot injury and the Celtics closely monitoring Kevin Garnett’s right knee, the team needs more from its bench. Tony Allen is getting his share of minutes, but his play has regressed.

The most pleasant surprise is Brian Scalabrine, who has flourished in two starts in place of Wallace. He has scored 20 points in the past two games, equaling his total from all of November. More minutes have made him more confident.