SALT LAKE CITY -- Boston Celtics president of basketball operations Danny Ainge pledged to be opportunistic this summer, and by maintaining salary flexibility through the initial stages of free agency, the Celtics were able to add a two-time former All-Star on Tuesday by agreeing to a trade that will soon deliver big man David Lee.

With the Warriors seeking luxury tax relief, Trader Danny bundled Gerald Wallace's bloated-but-stretchable $10.1 million contract with non-guaranteed filler in exchange for taking on Lee's bulky contract.

The 32-year-old Lee is making $15.5 million this season, a number the Warriors didn't want to stomach given his reduced role. The team will see immediate savings on its tax bill, and Golden State will have the option to trim even more money if it explores using the stretch provision on Wallace (spreading out his cap hit over the next three seasons; Lee was not able to be stretched since he inked his deal before the last collective bargaining agreement).

The Celtics get a 32-year-old big man who saw his minutes evaporate last year in part due to injury but also the emergence of Draymond Green. Through it all, Lee quietly embraced his diminished role and was rewarded by helping the Warriors to an NBA title. Lee averaged 7.9 points and 5.2 rebounds over 18.4 minutes per game last season but was an All-Star as recently as the 2012-13 season, when he posted 18.5 points and 11.2 rebounds per game for Golden State.

Lee joins a Boston frontcourt that already added Amir Johnson this summer (and re-signed Jonas Jerebko). A young core remains in Jared Sullinger, Kelly Olynyk, Tyler Zeller and recent second-round draft pick Jordan Mickey. Lee immediately helps Boston on the glass and is a pure post-up presence on a team where most of the bigs prefer to play on the perimeter.

There's virtually no risk here for Boston, other than crowding the frontcourt a bit. It does make you wonder if the team will explore additional moves. Sullinger's name danced in trade speculation around the draft, and Boston soon has to decide on his future (barring a surprise extension, Sullinger would be on pace to be a restricted free agent next summer).

Lee is only pegged here for a year. He'll have motivation to re-establish himself with a chance to play his way into another quality payday, particularly with a spike in the cap looming. But Boston's salary flexibility gave the Celtics the chance to take a flier on him. When you consider Wallace's limited role the last two seasons, it seems like a particularly good on-court deal for the Celtics.

And if Lee isn't healthy or simply doesn't have it, that's $15.5 million coming off the books next season when the Celtics, again, hope to have the sort of flexibility to make things happen.

Let's reset Boston's current roster/cap commitments after this move. A look at Boston's current guaranteed salary commitments for 2015-16 (assuming first-round picks are signed at typical 120 percent of the scale):

David Lee -- $15.5 million

Amir Johnson -- $12 million

Avery Bradley -- $7.7 million

Jae Crowder -- $7 million

Isaiah Thomas -- $6.9 million

Jonas Jerebko -- $5 million

Marcus Smart -- $3.4 million

Evan Turner -- $3.4 million

Tyler Zeller -- $2.6 million

Jared Sullinger -- $2.3 million

Kelly Olynyk -- $2.2 million

Terry Rozier -- $1.8 million

James Young -- $1.7 million

RJ Hunter -- $1.1 million

Boston is committed to $73.8 million for 14 players (and that total does not include second-round pick Mickey). The Celtics will, eventually, move back above the salary cap, but, for the purpose of roster compilation this offseason, will initially dip below the cap for the signings of Johnson and Jerebko and the addition of Lee. After those moves are processed, the team can re-sign restricted free agent Crowder whose initial cap charge is merely his $1.2 million qualifying offer.

Boston is still tip-toeing that projected cap line with those initial moves but has some wiggle room based on the salary structure for guys like Johnson and Jerebko (escalating, descending or flat deals). The Celtics also currently have two non-guaranteed players on their roster in Phil Pressey (a July 15 guarantee date looming) and Chris Babb (a player signed at the end of last season who seems likely to be included in the Golden State swap). Pressey, if he remains, faces long odds to muscle onto the roster and must hope another trade alleviates the crunch.

Alas, Boston is currently bloated. That's why big man Colton Iverson, a 2013 second-round pick who has been stashed overseas the past two years, left the summer squad to pursue overseas opportunities.

By dipping below the cap, Boston will have to renounce its trade exceptions so those are no longer in play as part of roster construction. The Celtics still have their surplus of draft picks that could help facilitate deals.

What happens now? With the addition of first-round pick Rozier and the team's desire for Smart to play pure point guard, Evan Turner appears a bit expendable. He was a valuable Swiss Army Knife last season, but his role is murkier as Boston's younger players start developing at his positions. Turner has a salary-friendly deal and could be of value on the trade market.

Then there is the growing jam up front. Boston must decide which of the young bigs fit their future plans and consider the options for the others.

One thing is certain: The Celtics will remain opportunistic. More opportunities will arise as teams start massaging their rosters and cap numbers. Trader Danny will be ready to field their calls.