Let the frenzy begin

While the Rockets prepare for twin tracks of free-agent strategies — with and without a roster-changing addition of Jimmy Butler — the rest of the league could be in for one of the wildest, most consequential summer overhauls on record. • Like the playoffs, it had been unthinkable that such a thing could occur without including LeBron James. But from stars to significant role players, the NBA could be headed to enormous, league-shifting change. • The Rockets typically will try to force their way into that mix, targeting Butler, a Tomball native and a close friend of James Harden’s, as their top priority. That would take a sign-and-trade agreement with the 76ers, who are far more determined to keep Butler than to see what they can get for him. • At the same time, the Rockets hope to add a significant role player with their midlevel exception, rather than spreading that $5.7 million around, with sources indicating Raptors guard Danny Green sits atop their list.

If the Rockets deal center Clint Capela to facilitate a sign-and-trade for Butler, they could try to lure DeAndre Jordan home to Houston, though he can likely earn much more than midlevel money, or try to land Kevon Looney. • While the Rockets prepare to dive in to the deep end of the free agent pool or are left working around the edges, there could be fascinating free agency battles, with the league’s glamour teams competing with franchise’s that were once laughingstocks. • The Celtics and Lakers have enormous work to do — assuming the expected Boston exodus occurs — and tons of cap room. But the Clippers and Nets will drive much of the free-agency action. The Bulls, Mavericks, Pacers and Pelicans also have in excess of $20 million in cap space. • There is a chance for spending to reach the 2016 cap-spike levels. Here’s a look at some of the market. Free agents can begin reaching agreements with teams at 5 p.m. Sunday and can officially sign beginning Saturday.