To be honest, Id rather start focusing on younger players at this point.
What young player out there is going to sign for the vet minimal? I mean one that will matter long term.
Right now, the Celtics have the right focus, title contending bench.
Worry about youth and the next Celtics rebuilding project when they get there.
Bingo, you have bingo!!! Let's play a little game. Ranking players from 1-10, 1 being the worst, 10 being the best. You can go out right now and get a player that will be a 7 for the next two years and then retire after that, or a player that will be a 5 next year, maybe a 6 the following, and could maybe be an 8 somewhere down the road, but for twice the contract lenght and similar (slightly higher) yearly cost. Now, let's also add to that formula the fact that you have a team who won a title two years ago, has most of the same pieces still around, and is built to win NOW, not later. So, what's best for your team? You take the sure thing, for the lower cost. And you hope that a couple years from now you'll be able to add a big free agent when one of your guys leaves (Joe Johnson when RayRay says byebye?), as well as making wise moves in the draft.