``You always have to get better,'' he said. ``Even if we'd have won the championship this year, we still would have done a deal like this if it was available.''

Sure, but when Ainge sees Shaquille O'Neal going to the Cavaliers, Vince Carter to Orlando, Ron Artest to LA and Richard Jefferson to the Spurs, he knows that standing pat would have been falling flat.

Just as important, perhaps, his players see it that way, too.

``I think we did have to do something,'' said Paul Pierce shortly after Wallace was introduced yesterday. ``I mean, you look around the whole league and it's like all the teams at the top got better. For us not to do anything would be to say, `Hey, we're losing this race.' So it was a must for us to go out and get Rasheed.

``The Lakers got Ron Artest, Shaquille went to Cleveland and Vince went to Orlando, so all the teams at the top got better. We had to.''

Ainge's coach believes the Celtics may have even skipped a beat. The team finished with the third-best record in the league last season despite missing Kevin Garnett down the stretch, but Doc Rivers thinks the roster was injured before KG went down.

``I thought when we won it, we were the only team coming into last year that took away from our team and really didn't add to our team,'' Rivers said. ``Orlando added to their team and Cleveland added to their team, but we kind of took away from our team (with the losses of James Posey and P.J. Brown). So I did think we needed to add some pieces. Hopefully we're not done.''

Wallace will be an interesting piece, to say the least. Rivers can put him at center to draw O'Neal away from the basket. He can use him with Garnett to allow easier switches when Dwight Howard and Rashard Lewis are picking for each other. And Wallace will help spread the floor to give Pierce more room to maneuver against Artest.

Just as the Celtics watched with interest as their intimate enemies made key additions, so now must those adversaries contemplate a world where Rivers can reach onto his bench and produce a multi-faceted big man.

``I think when Kevin was traded here two years ago, it put the NBA on notice,'' said Ray Allen. ``A lot of people sat back and they automatically pushed us to the top. They were a little afraid of us, and I think the same thing has happened now that we've added Rasheed to our roster.

``Sometimes not doing something is doing something. Sometimes you do something and it hurts your team. So it had to be the right something. I knew when Rasheed was available that it was the ultimate do something that we needed to do.''

The Celtics had to come up big if they hope to make it out of the East. They could not hope to negotiate a peaceful settlement when all around them plowshares are being turned into swords.

``I think for a long time the power has been out West on paper, but it does seem as though with Cleveland and Orlando and us that the power has shifted,'' said Allen. ``We've now got three power teams in the Eastern Conference, and then ultimately what that does is raise the level of the teams we play against every night. There's a ripple effect.''

Without a Wallace, the Celtics may well have drowned in the undertow of that ripple.

- sbulpett@bostonherald.com