Allen ready to come out firing

Ray Allen looks to pass here, but he'll be playing a more prominent role as a shooter, Celtics coach Doc Rivers promises. (Charles Krupa/Associated Press)

WALTHAM - When you are considered among the best pure shooters in the NBA, you get used to being a team's first offensive option. But last season, Ray Allen had to adjust his expectations, spending most of the time as a comparative afterthought in the Celtics' attack.

Allen was a highly regarded afterthought, of course, and by the final playoff series, he had not only become a first option at times, but he was the only Celtic considered invaluable enough to play the entire 48 minutes of a game.

Allen's profile has been raised this preseason. The Celtics spent much of their practice time in Newport, R.I., running plays to set him up on the perimeter.

"I thought he had the best camp," coach Doc Rivers said. "He played great and we put more in to accent him. It was tougher last year for him because we had to get Kevin [Garnett] involved in the offense and Paul [Pierce] was already involved. We only had a certain amount of time and he was almost the third thought.

"Now he knows where to get his shots in the offense and guys know how to find him."

But Rivers is not keeping score by field goal attempts.

"If Paul and Kevin take less shots and Ray takes less shots, we win," Rivers said. "It's not about the amount of shots they take. It's all about the amount of games we win. And we should be a better offensive team this year."

Allen, 33, attempted 986 shots last season, the first time he had fewer than 1,000 in a full season since his rookie year, 1996-97. Garnett had his lowest shot total (990) for a full season since his first year as a professional, and Pierce had the lowest total (1,098) of his career for a full season.

Allen's shooting percentage (.445) was slightly less than his career mark (.446), and his scoring average (17.4) was his lowest since 1998-99, when he averaged 17.1 points in 50 games for Milwaukee.

In the playoffs, Allen's shooting dipped (.428), though he set an NBA Finals record by converting 22 3-pointers.

"I never thought I was in a slump in the playoffs," Allen said. "I was missing five or six shots but I was only taking seven or eight shots. When you do that, the percentage doesn't look great. But in the past, I was missing five or six shots but I would be taking 18 shots.

"Missing never bothers me as a shooter. Shooting is all about confidence. If I miss a shot, I know I am going to make the next one. It's like when we held LeBron James to 4 for 18 in the playoffs. The next game, he just kept shooting. He might miss 11 shots but he kept shooting."

In the six-game final series, Allen averaged 20.3 points (second to Pierce) and 12.2 field goal attempts per game. Allen rivaled Pierce for Finals MVP, with Pierce's overpowering second half in the Game 4 victory over the Lakers likely carrying him to the award.

But, slump or not, Allen's shooting did fall off for a while in the playoffs.

From Game 6 in the first round against Atlanta until Game 2 in the Eastern Conference finals against Detroit, Allen was 34 for 102 (.333) from the field, his 3-point accuracy even more uncharacteristic at 6 for 38 (.156). But Allen recovered with a 25-point performance (9 for 16) against the Pistons and finished strong in the conference finals and NBA Finals.

Allen will likely be rested for long stretches in tonight's preseason opener against Philadelphia in Amherst.

"We know what the ultimate goal is," Allen said. "The process starts [tonight]. I don't know how much we will play, but last year we didn't play a whole lot of minutes in the preseason. I got the most rest in my career.

"We like to go to the preseason and win games, but our ultimate goal is to win that first [regular-season game]."

Frank Dell'Apa can be reached at f_dellapa@globe.com.