A top 10 defense
The Spurs finished just 17th in defensive rating this season, marking their third straight season with a below-average defense. San Antonio will need to get back into the top 10 next season to be more competitive in the Western Conference. The last time San Antonio finished in the top 10 in defensive rating, during the 2017-2018 season, they also happened to make the playoffs.
Fortunately, they have the personnel needed to make a significant improvement on the defensive end. Derrick White, arguably the Spurs' best perimeter defender, appeared in just 36 of 72 games this season. A healthy White could have a big impact on the defense next season, especially when paired with Dejounte Murray, Keldon Johnson, and Jakob Poeltl in the starting lineup.
Meanwhile, Poeltl emerged as an elite rim protector this season and, with increased minutes, could make an even greater impact next season. His presence in the paint allows the Spurs' young guards and wings to be more aggressive defending on the perimeter and potentially force more turnovers.
It's worth also keeping in mind that one of the Spurs' emerging defensive stars in Devin Vassell only played limited minutes this past season. That being said, given the flashes of impressive defense he was able to show in that limited time, playing a more important (and consistent) role next season could do wonders for the team's defense.
Were San Antonio able to make a return to being a top 10 defense, they’d give themselves a much better chance of winning than they've had in recent seasons.