The pillar of what made the Phoenix Suns what they were in the 2025-26 season was the defense.

Phoenix managed to hang around the top-10 of the league in defensive efficiency all season. This came on the back of surprising rebounding efforts, a clear vision from head coach Jordan Ott, and breakouts from individual players such as Collin Gillespie.

Despite this, major questions are arising due to distinct personnel changes, along with the belief that last season's output is unsustainable. 

As mentioned above, the personnel shifts carry much weight in the skepticism about the unit's aptitude to staying in the top 10 this season. 

This includes Sam Quinn (CBS Sports), who has the Suns as the 17th best defense in the league heading into game one.

While Grayson Allen and Royce O'Neale aren't exceptional defenders, the sam can be said for the incoming Miles Bridges. There's a world in which the fit between Bridges, Green, Booker, and any other personnel that Ott opts to group together is extremely clunky, gifting easy lanes to the rim up, as well as ample second-chance opportunities.

The other question resides in just how much the best defenders on the roster will see the floor, as well as the growth from Phoenix's young center duo.

Jordan Goodwin's role is a possible litmus test when it comes to how high the ceiling of the perimeter attack can be.

The ultimate determining factor is in how second-year Khaman Maluach and third-year Oso Ighodaro progress.

Maluach is largely passing early tests, particularly in an impressive showing when facing San Antonio Spurs superstar Victor Wembanyama head-on in the Saturday matchup. The Duke product appears to be rapidly adjusting to the speed of the NBA game, and is becoming more adept to changing the trajectory of shots in the lane rather than looking to just block shots. 

Ighodaro is the most polished rim protector at the moment, but still faces definite questions - particularly as a defensive rebounder, and as a smaller frame in comparison with his typical matchups on a game-by-game basis. 

This duo still projects to be one of the more talented on the defensive side of the end - making improvements around the margins will raise the bar for a unit that spend much of last season overachieving.