WALTHAM — The Celtics’ bench rotation is noticeably tighter during the playoffs, the regulars pared to Tony Allen, Glen Davis, and Rasheed Wallace, and in smaller doses Michael Finley. It makes the margin for error slimmer, with the consequence of poor bench play being longer minutes for the starting five.
Rivers has rarely reached too deep into his bench. Marquis Daniels and Nate Robinson have each played in six games this postseason, with Daniels being called on during the second-round series against Cleveland as another body to throw at LeBron James. Shelden Williams also saw the floor against the Cavaliers, with the Celtics needing all hands on deck to thwart Shaquille O’Neal.
Rivers said he isn’t reluctant to use anyone on his bench if necessary — the key words being “if necessary.’’
“Obviously, you want guys to be efficient so you don’t have to extend your minutes, but I would be willing to do it if I thought we had to,’’ Rivers said yesterday. “If I thought a guy wasn’t doing his job, or a guy was injured or in foul trouble, I have faith in the guys that I haven’t played. I have no problem putting them in if I have to do that.’’
The bench has given the Celtics lifts throughout the postseason, but comparing these reserves with the cast from Boston’s championship run in 2008, Rivers said the group that featured James Posey, Eddie House, P.J. Brown, Sam Cassell, Leon Powe, and others was less of a mixed bag.
“They were pretty consistent,’’ Rivers said. “You could pretty much write down what Posey was going to do, and P.J. This group, you just don’t know from game to game, and that makes it more challenging.
“The only way you’re going to win is somebody on the bench has to play well. And it’s going to have to be multiple people, and we’re getting that.’’
After averaging 13.5 points in the second round, Pierce averaged 25 points in the first two games of this series, often victimizing Carter. Barnes, who played 25.9 minutes a game during the regular season and saw long minutes against Charlotte (27) and Atlanta (22.5) in the first two rounds of the playoffs, has had his playing time dip to 18 minutes a night during this series, hampered by a sore back that initially gave him trouble after Game 3 of the second-round series against the Hawks.
Barnes played through the pain in Game 1 against the Celtics, but was torched for 25 points by Ray Allen.
“I haven’t been playing as much due to my back and, I guess, maybe due to matchups,’’ Barnes said. “Hopefully [tonight] I’ll be able to stay out there a little longer and help my team. I’m ready for whoever. I want to guard Pierce. We’ll see.’’
Julian Benbow can be reached at jbenbow@globe.com. ![]()




