WALTHAM -- When the NBA re-opened for business last Friday, Danny Ainge had six players under contract, no cap room and only a handful of assets he could use to acquire players. Despite such scarce resources, Ainge nonetheless launched an ambitious plan to land one of the two marquee names available in Hornets guard Chris Paul. When that didn’t work he hatched a fairly ingenious plot to acquire free agent forward David West using an aging center with bad knees on the last year of his contract.

Neither plan worked for reasons largely beyond his control. Ultimately, he didn’t have what the NBA wanted for Paul and he couldn’t do anything about the Pacers offering David West more money. But Ainge still had an immensely successful 72 hours. He built a bench using conventional and unconventional means and did so without harming the team’s flexibility for next year.

“The biggest challenge is that we had limited resources with the collective bargaining agreement,” Ainge said. “We have a lot of money tied up in our four All-Stars and we didn’t want to make long-term commitments.”

Ainge signed veteran big man Chris Wilcox using the taxpayer mid-level exception of $3 million, but did so for only one year instead of the three allowed under the CBA. He added Marquis Daniels and Sasha Pavlovic one one-year deals, adding much-needed depth on the wing behind Ray Allen and Paul Pierce. Where Ainge really scored value was getting two players in the trade market -- Brandon Bass and Keyon Dooling -- using his own unrestricted free agents and a cap exception.

Ainge acquired Dooling using a traded player exception that was created when he traded Daniels to Sacramento after Daniels injured his spinal cord and the Celtics needed a roster spot. Dooling is found money, a player conjured out of thin air that cost the Celtics nothing more than money and the rights to a player named Albert Miralles that were acquired in a long-ago deal involving Antoine Walker. (Ainge also got a protected second round pick).

Acquiring Bass was another savvy move. Ainge traded two unrestricted free agents -- Glen Davis and Von Wafer – to acquire a player who fill a similar role as Davis for much less money. Bass has a player option next season for $4 million that is both reasonable and very tradeable if he decides to exercise it, while Davis was given a four-year deal for $26 million by the Magic. That’s exactly the kind of contract Ainge was trying to avoid.

“Brandon is just a real high character, high-energy player,” Ainge said. “He’s athletic. He’s a fantastic mid-range shooter. Just a real active player with a lot of athleticism and energy. He fits our timeline too. We’re trying to have great success this year and his contract length sort of fits into our timeline.”

He also was able to re-sign restricted free agent Jeff Green to a one-year deal, rather than a long-term extension. Green’s contract is on hold while he undergoes more after Ainge said something came up on his physical. “We anticipate he’ll be here,” Ainge said. “I don’t think he’ll [be out] very long. He’s just going through the tests again today and [Tuesday], and we should be fine.”

With Green on hold, that gives the Celtics 13 players after JaJuan Johnson and E’Twaun Moore signed their rookie deals. Most importantly, only five are signed beyond next season: Rondo, Paul Pierce, Avery Bradley, Johnson and Bass. Even if Bass picks up his option, the combined value of their deals is close to $35 million, leaving the Celtics ample room under next year’s cap, which is likely to be close to the $58 million mark that is set for this season.

That cap room is theoretical. If Ainge wants to use all of that cap space he would have to either re-sign players like Kevin Garnett and Ray Allen for much smaller amounts or renounce their rights when they enter free agency. That’s important to note because there’s no telling what Ainge has in mind for next year.

If Paul or Dwight Howard become free agents, he could step in and offer either a max deal. If not, he has created financial flexibility to acquire players via trade or free agency. Ainge has walked a tightrope during the big three era in maintaining what they have now, while also keeping an eye on an uncertain future. He has so far resisted blowing up the Garnett-Pierce-Allen nucleus, but that doesn’t mean he hasn’t explored his options.

“I think our guys still feel they can win and we’ll just have to see,” Ainge said. “It’s hard to know when guys are getting older how much they have left. They surprised me the last couple of years. I remember two years ago when it wasn’t looking very good the second half of the year and they got to Game 7 of the NBA finals on the road. These guys have a lot left in the tank. I think we’ll know more about that a month or two into season.”

Assuming Green does join the team, the Celtics are two deep at every position with Dooling, Daniels, Green, Bass and Wilcox forming a veteran-heavy reserve unit that is also younger than previous years. Johnson and Moore are older rookies who played four years at a major college program and more is expected of Bradley in his second season, especially with Dooling around to handle backup point guard duties. The Celtics remain convinced they can get something more out of Pavlovic than what he showed in limited action last season.

Is this a perfect roster? No.

They remain dependent in part on Jermaine O’Neal making it through the season and while Doc Rivers has talked about using Garnett at center this season, that plan would have looked a lot better with a player like West by his side. Bass and Wilcox can step right into their roles and on the surface would seem to have the ability to mix and match with Garnett, but if anyone goes down with an injury – particularly O’Neal and Garnett – they will be very thin up front. Johnson provides length and shooting ability and Greg Stiemsma is an interesting developmental prospect, but both players are obviously unproven.

“Yeah, probably so,” Ainge said when asked if they needed another big man. “That would be nice. We’d like somebody that can play and is big.” There aren’t many of those available.

The reserve unit also lacks a dependable wing shooter behind Allen. Daniels is a versatile player whose primary strength is his defense and ability to guard multiple positions. Bradley could be an attack-dog defender in the mold of Tony Allen, but his offense isn’t nearly as advanced. Dooling is a good shooter and could play off guard, but he’s undersized for the position. Then there’s Moore who drew raves from Doc Rivers on his first day as practice.

“The two spot will have to be determined,” Rivers said. “Somebody’s going to have to take it.”

What Rivers does have, at least on paper, is a deeper roster and a more versatile bench than he’s had in years. “I feel good about it but I don’t know what it is,” Rivers said. “I do like it because we have veterans on it and guys who know how to play.”

Ainge may not be done. He wouldn’t commit one way or another and history has shown us that he is unafraid to make a move at any time if he feels it benefits the franchise. He may have missed on his two main targets, but in 72 hours he assembled a deep, workable team for this year and left the future as wide open as it was when he started.