The answer starts with Anthony, whose role is uncertain for the moment.
Some reports indicate the future Hall of Famer (yes, future Hall of Famer) could come off the bench. Doing so would mean an obvious change in sentiment from a year ago, when Anthony wouldn’t even hear out the possibility of becoming a reserve with the Oklahoma City Thunder. If he is in the starting lineup, it grows tougher for Houston to send its bigs to the perimeter.
Anthony’s flaws become more exploitable during a playoff series. That showed during the Thunder’s six-game loss to the Utah Jazz in last season’s first round. Jazz guard Donovan Mitchell called for ball screen after ball screen until he could get Anthony to switch onto him. The veteran forward would often break coverage in doing so. Once Mitchell got what he wanted, a one-on-one matchup with a 15-year veteran far heavier-footed than he, the game was his. By the end of the series, the Thunder were sitting Anthony during closing time.
There is, however, a major difference between what Utah did to Anthony and what the Celtics could: Boston wouldn’t need to worry about forcing switches. It could go right at him.
Assuming the Celtics’ projected starting lineup (or at least their projected most used lineup) is in the game — meaning point guard Kyrie Irving, wings Jaylen Brown, Jayson Tatum and Gordon Hayward as well as center Al Horford — Anthony would be guarding someone who can create against him from the start. Hayward can iso and score for himself or find others. So can Tatum. Brown isn’t as optimal a choice as the first two, but he can facilitate offense on his own.
Even Horford could find ways to take advantage — either with or without the ball. He can set screens and send the Rockets defense into confusion. He can create from the top of the key. Old-school posting up might not be the way to go, considering Anthony’s best defensive trait is probably his strength. (That’s one of a few reasons Anthony could end up playing center with bench lineups, a role the Rockets used Tucker in last season.)
But the Celtics can iso on Anthony. They make him guard funky pick-and-roll combinations that have him defending the front ends with someone like Harden defending the screeners. (Both players are more comfortable guarding opposite ends of such plays.) Boston can attack from there. You can bet that’s exactly what it’d do as long as Anthony received time in the series.