Once the Celtics  interest in Rasheed Wallace  became known, and once the other free agent prizes began to find teams, it became more and more apparent that the Celtics had to get a deal done with Wallace. Not because Cleveland traded for Shaquille O’Neal  or because Orlando added Vince Carter , but because Wallace is exactly what the Celtics need, and there is no one else remotely like him available.
The Celtics came into this offseason with three identifiable areas of need: A backup point guard who can run the team competently when Rajon Rondo  goes to the bench, a versatile swing man–preferably one who can guard at least two positions, make a jump shot and give Paul Pierce  some real rest–and a big man. Already in luxury tax territory and armed with the mid-level exception the Celtics had one big play to make and to that end they wisely stayed out of the limited point guard pool and the big-money small forward arms race. In zeroing in on Wallace, the Celtics identified their biggest need and spent accordingly.
Wallace’s agent, Bill Strickland, made noises during the courtship that a selling point for Wallace was assurances that the Celtics were not done making moves. They still have the bi-annual exception (projected to be around $2 million) and if they can land someone like Grant Hill , that would represent the best-case scenario. But there are still a few solid veterans looking for new homes, like Marquis Daniels , Quinton Ross and Anthony Parker , as well as in-house options like Brian Scalabrine , JR Giddens and Bill Walker . The Celtics have options, in other words.
But landing a quality big man was always the top priority and in Wallace the Celtics not only get an intelligent, versatile veteran who has been on a championship team, they also get something they did not have at all last season: protection in case Kevin Garnett  or Kendrick Perkins  gets hurt.
Wallace is much more than an insurance policy, however. His offensive game may have gotten a little too perimeter-heavy  last season, but his style of play fits perfectly in the Celtics system which rarely utilizes a low-post option. Additionally his ability to guard power forward and centers, particularly centers, is a huge addition for the Celtics who haven’t really had that player during the Big 3 era (except for PJ Brown’s playoff run), and they have had to ask undersized power forwards like Leon Powe  and Glen Davis  to play out of position.
The Celtics still need a backup point guard and seem content to try to lure one with the veteran minimum like maybe Ty Lue (one of Kevin Garnett’s best friends) and that small forward, but they just solved their biggest offseason problem with the addition of Rasheed Wallace.