Paul Pierce tries to drive around Cleveland’s Anderson Varejao in the second half Tuesday, but the ball was knocked away.

The Providence Journal / Glenn Osmundson

WALTHAM, Mass. — Celtics coach Doc Rivers is expecting All-Star guard Ray Allen to break out of his shooting slump tonight.

Allen is coming off two back-to-back horrific shooting performances.

Despite telling his teammates that Game Seven against Atlanta was the most important game of his career, the eight-time All-Star shot just 3-for-12 from the field and scored only seven points.

He followed that up tying his worst shooting performance of his career — 0-for-4 from the field, scoring no points in more than 37 minutes of action. It was his worst-ever playoff game and it broke an 852-consecutive-game scoring streak dating to 1997, when he played for Milwaukee.

The Celtics were able to get away with Allen’s poor shooting in their last two outings, but how long can the Celtics keep winning if Allen continues to struggle from the field?

“We have to get him more touches in better rhythm,” Rivers said.

Allen is confident that he’ll break out of his slump.

“For myself, I never say that I’m out of rhythm because you can miss 10 in a row and if you make your next , you’re good,” Allen said. “As a team, normally I’ll step into an easy shot or get something in transition, but it seemed like we were just one step off. The good thing was that we were still passing the ball to each other.”

Rivers said that he expects Cleveland to trap Kevin Garnett more in the post tonight, which could lead to open looks for Allen.

Pierce, too, looks to recover

Allen isn’t the only Celtic who is trying to break out of a scoring slump. Fellow All-Star Paul Pierce was limited to just four points Tuesday, but he did spend a lot of energy on the defensive end helping to shut down Cleveland superstar LeBron James. The Celtics limited James to 12 points on 2-for-18 shooting (11.1 percent).

“Hopefully, I can turn my offense a little bit around [tonight] to where I can take a little pressure off of Kevin [Garnett],” Pierce said yesterday at practice. “If I can do that and go out there and do the same defensive work, I think we’ll be fine.”

Pierce is averaging 16.3 points, 4.6 rebounds, and 4.6 assists per game in this year’s playoffs. Pierce led the Celtics in scoring during the regular season, during which he averaged 19.6 points, 5.1 rebounds, and 4.5 assists per game.

“[Pierce and Allen] are great players,” Cleveland coach Mike Brown said. “We need to try and keep those guys off balance, because in the future it will be hard to keep those guys to scoring only four points. But we’ll try.”

“I don’t expect [Pierce] to play like he played [Tuesday] — him or Ray,” James said.

Posey good to go

Boston forward James Posey injured his side in Game One but said that after Tuesday’s game that he was fine and would play tonight.