As we know the Celtics are heading towards a retooling, and while Tatum is out, the main goal isn't winning a championship like the past 3 years but getting cheaper and fall under the second apron. A way could be trading away Jaylen Brown to the Rockets: Houston is in win now mode, as they just traded for KD, and they can take advantage of the rookie-contracts of their main pieces, Thompson, Jabari and Tari, to add another star.
The trade would involve VanVleet huge expiring contract and Landale, good bench piece, and the Suns picks Houston was able to keep in the durant trade + a Nets swap that could be a high pick.
In this way, after getting Anfernee Simons, Boston would have at least $103.1M of expiring contracts (Porzingis, Simons and VanVleet) in the 2026/27 offseason, and can build a new team to compete with Tatum, and in addition, have three very good picks in the following years to add young and cheap pieces, or use them in another trade.
Ofcourse both teams would be skeptical to do a trade like this, Boston probably doesn't want to get rid of Jaylen Brown, and Houston might want to keep VanVleet's leadership in the building, after the departure of Brooks, and Brown's contract would be very heavy for Houston who has to give new contracts next offseason to KD, Jabari and Tari.