They've signed Rasheed Wallace, giving them an extraordinary backup big man who'll bring versatility to their bench.
They've gotten a commitment from Marquis Daniels, who will give them crucial bench minutes in relief of Paul Pierce and Ray Allen.
They've signed Shelden Williams on the cheap, a solid insurance policy should one of their other bigs get hurt.
They've hammered out a reasonable extension for Glen Davis, locking up one of the team's rising stars.
And, perhaps most importantly, they resisted the temptation to rashly trade up from the No. 58 pick in this summer's draft. In doing so, they've kept the team's superb nucleus intact.
When the season ended, all the Celtics had was a starting five, and even that was on the verge of being torn apart. Now they have the league's best starters and an unexpectedly deep bench, to boot.
There's only one thing they're missing.
Rajon Rondo is one of the game's best young point guards, but he runs the risk of entering the preseason with no backup in place. Rondo has the talent to give you a triple-double on any given night, but if he's worn out come April, he won't still be doing it in the playoffs. Not like he did this spring.
Rondo needs a backup. And so far, neither coach Doc Rivers nor GM Danny Ainge has said anything encouraging about the second point guard situation.
Here's what they have said:
Daniels and the recently re-signed Eddie House, according to the Celtics' brass, are the two options. The C's have tons of wing players, and these two backups supposedly have the flexibility to move to the point in a pinch.
Excuse me for being skeptical.
Daniels is not a point guard. He just isn't. At 28, the 6-foot-6 former Pacer had a breakout season as a forward last season, averaging a career-high 4.6 rebounds per game, including 1.5 on the offensive end of the floor. He was physical, he was athletic and he was a stellar one-on-one defender against opposing small forwards.
Moving him to the point would be a step in the wrong direction. With 114 assists and 94 turnovers last season, Daniels gave the C's reason to question his passing ability — but that's OK. It's not his skill set, and the C's knew that when they first went after him. He's a small forward — that's why he's here.
As for House, he's pretty much the definition of a shooting guard. He thrives on the wing, where he can chill out and wait for the open jumper — and he hits them like no one else. Last season, he led the C's with his 44.4 percent shooting from beyond the arc.
If the Celtics want House at his best, they should use him at the two when Rondo is on the floor. That way, Rondo, with his freakish athleticism, can draw the attention of wing defenders, thus creating more open looks for House. House needs those shots to be effective. Moving him to the point would completely change the way opposing defenses play him. And that can't be good.
For the Celtics, there are really only two satisfactory explanations for this Rondo backup situation. Neither involves Daniels or House.
1. Lester Hudson, the Celtics' selection with that No. 58 pick in the draft, is the team's secret weapon, and they're keeping him under wraps until he comes off the bench this fall. Hudson broke his finger in summer-league action, but he's got talent when healthy. Can he run the point? There's a chance.
2. Maybe the Celtics are still working on making a move.
There are several decent backups still available on the scrap heap. Most notably, there's Bobby Jackson, who's getting on in years but played decently for Sacramento last season. There's also Tyronn Lue, who was an okay backup for Rafer Alston in Orlando last season. He's also on the open market.
What the Celtics would like, ideally, is a guy with experience playing for a championship contender. Rondo, of course, has it. Will his backup have it, too?
That's the question. And it needs to be answered in the coming weeks, or else the Celtics' depth won't end up quite as strong as it's cracked up to be.
The Celtics have done a lot, but here's the point: They want to be deep at the game's most important position, and that is the point.