WALTHAM — Before their open practice on Tuesday, Celtics  coach Doc Rivers  introduced their newest player, Carlos Arroyo , to his teammates. His new team proceeded to pummel him like baseball players do at home plate after someone hits a game-winning home run. With that bit of bonding out of the way, Arroyo began his crash-course in running the Celtics’ offense.
“He’s a point guard,” Rivers said emphasizing the last two words. “He’s been a point guard all of his life. Some of the stuff he’ll pick up pretty quickly.”
The Celtics have essentially played without a true backup point guard since Rajon Rondo  took over the starter’s job in 2007. Eddie House  and Nate Robinson  — two shoot-first small guards — mainly filled that role, while the Celtics also tried Sam Cassell and Stephon Marbury  as late-season experiments, with decidedly mixed results.
“It’s nice,” Rivers said of having a true backup point. “It’s just going to take him some time, but he knows how to run a team. That’s going to be great for us.”
Delonte West  is supposed to be that player, but he has been unable to stay on the court; missing time with a broken wrist and a sprained ankle. Rivers said that West was definitely out Wednesday against the Clippers and called him “doubtful” for Friday’s Sixers game. The new hope is Sunday against the Bucks.
Rivers has been concerned about playing Rondo too many minutes. He has posted the following totals in his last six games: 43, 34, 42, 39, 42, 38. That 34 came in a relatively comfortable win over the Clippers. Rondo had to take himself out for a quick rest in the fourth quarter of their game against Golden State and looked a step slow on Sunday against the Bucks. While rookie Avery Bradley  has stepped in admirably, the Celtics desperately needed a veteran hand at the position.
Into that spot steps Arroyo, who started 42 games for the Heat this season before being waived to make room for Mike Bibby. The 31-year-old Arroyo is the definition of a veteran journeyman, having played for six teams (the Celtics are his seventh) in his nine-year career.
His best season came back in 2003-04 when he started 71 games for the Jazz  and averaged 12.6 points and five assists per game. Since then he’s bounced around between Orlando and Miami where he saw duty as a spot starter and backup. He was making 44 percent of his 3-pointers with the Heat, but he is a 34 percent shooter for his career.
“At this point in my career, everybody knows what I’m capable of,” Arroyo said. “Hopefully I can do a little bit more here and help the team. That’s what I came here for.”
Asked about what happened in Miami, Arroyo took the high road.
“I went from starting to not playing and I’ve got to respect that,” he said. “That’s coach [Erik Spoelstra ‘s] decision. My job is to stay ready. I’m a true professional when it comes to that and I understand how the NBA works. I was just waiting for my time and hopefully my time is now.”