Report: Celtics agree to acquire David Lee from Warriors for Gerald Wallace

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There is no such thing as an untradeable contract.

The Boston Celtics have agreed to acquire David Lee from the Golden State Warriors for Gerald Wallace, according to Marc Stein of ESPN.

It's an interesting swap of bad contracts, and it's surprising that no pick or additional consideration is heading to Boston to help grease the wheels. While Lee is a solid player, particularly on the offensive end, this trade could potentially save the Warriors substantial money.

Lee, who can't have his salary waived using what's known as the stretch provision, is set to earn $15.5 million for 2015-16, the final year of his contract. Wallace will earn $10.1 million, also on the last year of his deal, but Wallace can be stretched.

Doing so would lower his cap hit for this season to roughly $3.37 million, effectively clearing an estimated $12.1 million off Golden State's books. Because the Warriors are in the luxury tax, those savings are compounded even further, with the total cash savings to the organization estimated at anywhere from $30- to $34-million.

While that's a potential end-game for the Warriors, there's also the chance they keep Wallace and enjoy the salary and tax savings from the $5.4-million decrease in salary from the swap, an estimated $18 million in total. The current plan is to keep Wallace, according to Marc Spears of Yahoo Sports, adding another versatile defender to the embarrassment of them on Golden State's roster.

The Warriors have until Aug. 31 to use the provision on Wallace, giving them an opportunity to look for a trade partner.

The move won't cost the Celtics an equivalent amount, as they have the flexibility around the salary cap to take Lee in with no concern for the luxury tax. He'll add to a crowded frontcourt but will immediately be the most talented player in the group. With Wallace having no clear role with the team - he played 286 minutes last year - this is an upgrade that costs Boston nothing in terms of assets beyond cash and cap space.

While Lee's role with the Warriors was reduced significantly following his return from a back injury and the emergence of Draymond Green, the 32-year-old should be a bounce-back candidate next season. He has a versatile offensive game, with a handful of nifty post moves, ambidextrous finishing, decent range on his jumper, and is a solid passer from the elbows or the block.

He's a defensive liability, but so are most of the big men Boston has at its disposal. None of the other players on the roster are likely to approach the 18.2 points, 10.7 rebounds, and 2.9 assists that Lee averaged from 2008-09 to 2013-14, a stretch that saw him make two All-Star teams.