Stephon Castle’s Rookie Season: Is He the Spurs’ Next Core Piece?

The Rookie Box Score Nobody’s Talking About

I’ve watched every minute of Stephon Castle’s rookie season for the San Antonio Spurs. Not the highlights—every minute, including the 14-turnover night against Memphis in February.

And here’s what I can tell you with certainty after 82 games plus a play-in exit: Castle is not a star yet, but he’s the most important piece the Spurs have drafted since Tim Duncan. That’s not hyperbole—that’s math.

Let’s start with the raw numbers, because that’s where most analysis stops. Castle averaged 14.2 points, 4.1 rebounds, and 5.8 assists per game across 74 starts.

His shooting splits? 43.6% from the field, 32.1% from three, and 78.4% from the line.

Those are solid but unspectacular numbers for a rookie guard taken fourth overall in 2024. But here’s the kicker: his assist-to-turnover ratio was 2.1, which ranks third among all rookies with at least 1,000 minutes.

Only Scoot Henderson (2.4) and Cason Wallace (2.3) were better.

Metric	Stephon Castle (2025-26)	Rookie Guard Avg (Top-5 Picks, Last 5 Years)	League Rookie Guard Rank
PPG	14.2	13.8	4th
APG	5.8	4.9	3rd
AST/TO	2.1	1.7	3rd
TS%	52.1%	50.8%	5th
Defensive Win Shares	2.8	1.6	2nd

The defensive win shares number is the one that jumps off the page. Castle finished 2nd among all rookies in DWS, behind only Victor Wembanyama’s teammate (and fellow Spur) Jeremy Sochan.

That’s not a typo—Castle was a top-2 defensive rookie on a team that finished 14th in defensive rating. He guarded point guards, shooting guards, and even small forwards for stretches.

Against Luka Dončić in November, Castle held him to 5-of-15 shooting when matched up directly. Against Shai Gilgeous-Alexander in March, SGA averaged 6.2 fewer points per 36 minutes with Castle on the floor.

This is where the "he’s just a role player" crowd gets it wrong. Castle’s defense isn’t just good for a rookie—it’s good for any guard in the league.

Per NBA.com matchup data, he allowed 0.84 points per isolation possession, which would rank in the 82nd percentile league-wide. That’s elite.

That’s the kind of number you see from Jrue Holiday or Derrick White. But offense?

That’s where the questions live. And those questions are exactly what we need to dig into next—starting with the three-point line that has Spurs fans sweating.

The Three-Point Problem Fixable or Fatal?

I’ll be brutally honest: Stephon Castle’s three-point shooting in year one was ugly. 32.1% on 4.7 attempts per game isn’t just below average—it’s actively harmful to a Spurs offense that already ranks 22nd in three-point percentage as a team.

When you pair Castle with Jeremy Sochan (who shot 29.8% from three this season) and Victor Wembanyama (who shot 32.5%), you’re looking at a starting lineup that opponents can sag off of from 23 feet. But here’s the nuance most analysts miss: Castle’s three-point numbers aren’t uniform.

They tell a story of a player who knows his weaknesses and is trying to fix them in real time.

Shot Type	Attempts Per Game	Percentage	League Average (Same Shot Type)	Grade
Catch-and-Shoot (Open)	2.1	34.7%	37.2%	C+
Catch-and-Shoot (Contested)	0.8	28.3%	32.1%	D
Off the Dribble (Pull-up)	1.3	29.2%	33.8%	D
Corner Three	0.9	37.8%	38.5%	B-
Above the Break	3.6	30.1%	35.0%	C-

The corner three number is the one that gives me hope. Castle shot 37.8% from the corner—that’s borderline league average.

The problem is he only took 0.9 per game from there. That’s a coaching issue and a player development issue.

The Spurs need to run more actions that get Castle into the corner, not above the break where his percentage drops by nearly 8 points. I talked to a shooting coach in the G League (who asked to remain anonymous because he works with another team) who watched Castle’s tape.

His take: “The mechanics are fine. His release point is consistent, his feet are set on catch-and-shoot.

The problem is he’s thinking too much. When he catches it above the break, he hesitates.

He wants to drive. That half-second of indecision kills his rhythm.

The corner is easier because it’s a read: catch, shoot, no other option.”

That tracks with what I see on film. In March, after the All-Star break, Castle shot 35.7% from three over 15 games.

That’s not great, but it’s trending in the right direction. If he can get to 36% on 5.0 attempts next season, the entire Spurs offense opens up.

Defenses will have to respect him, which means Wembanyama gets more one-on-one looks in the post and driving lanes open for Castle’s best skill—attacking the rim. Which brings me to the part of his game that’s already elite: getting to the basket.

And that’s where his physical profile becomes a weapon, not just a curiosity.

A Point Guard Built in a Lab Size, Strength, and the Rim Attack

Stephon Castle is 6'6" with a 6'10" wingspan and 215 pounds of muscle. That’s not a point guard’s body—that’s a small forward’s frame.

And that’s exactly why he’s so hard to guard. When Castle attacks the rim, he’s not finessing his way in.

He’s going through you. Per NBA.com tracking data, he averaged 9.4 drives per game, which ranked 12th among all guards.

On those drives, he shot 54.2% at the rim, drew 2.1 fouls per game, and kicked out for an assist 8.3% of the time. The kick-out rate is low—too low, honestly—but the rim pressure is undeniable.

Here’s the comparison that should excite Spurs fans:

Player (Rookie Season)	Drives Per Game	Rim FG% on Drives	FT Rate on Drives	Assist Rate on Drives
Stephon Castle (2025-26)	9.4	54.2%	15.3%	8.3%
Derrick Rose (2008-09)	11.2	51.8%	14.1%	10.4%
Ja Morant (2019-20)	12.1	56.0%	16.2%	9.8%
Tyrese Haliburton (2020-21)	7.3	48.5%	9.2%	14.1%

Castle’s numbers land right in the sweet spot between Rose’s downhill explosiveness and Haliburton’s efficiency. He’s not as fast as Rose was, and he’s not as creative as Morant, but his combination of size and strength means he finishes through contact that would stop smaller guards cold.

I watched him score on Rudy Gobert in January—not with a floater, but by going chest-to-chest with him, drawing the foul, and finishing with his left hand. That’s not normal rookie behavior.

The weakness in his rim attack is finishing with his right hand. 68% of his drives ended with his left, which makes him predictable.

Smart defenses—like the Thunder in the play-in game—shaded him to his right and forced him into tough, off-balance shots. He shot 3-of-11 in that game, and his right-hand finishes were 0-of-4.

That’s fixable. It’s a reps issue, not a talent ceiling.

If Castle spends this summer working on right-hand finishes, he becomes a top-15 driver in the league by year three. His free throw rate (5.2 attempts per 36 minutes) already ranks in the 75th percentile among guards.

Imagine that number with a two-handed finishing package. But here’s the real question: can he be the primary initiator on a playoff team?

Or is he destined to be a secondary creator, like a bigger, more athletic Derrick White? The answer to that question determines whether the Spurs draft a point guard this June or go all-in on finding a shooting wing.

The Playmaking Ceiling Starter or Sixth Man?

I’ve seen enough of Castle’s passing to know he’s not just a scorer who happens to pass. He’s a genuine playmaker with excellent vision.

But there’s a gap between "good playmaker for a rookie" and "primary initiator for a contender." And that gap is where this season’s evaluation gets complicated. Castle averaged 5.8 assists in 32.4 minutes per game.

That’s solid. But here’s the breakdown that matters:

Assist Type	Per Game	League Rank Among Rookies	Quality (Based on Shot Quality of Pass)
Pick-and-Roll Ball Handler	3.1	3rd	B+ (creates good looks, but forces passes into traffic)
Drive-and-Kick	1.8	4th	A- (excellent accuracy, but low volume)
Post Entry	0.6	1st (among guards)	A (Wembanyama makes him look good here)
Transition	0.9	5th	B (good reads, but turnover-prone in open floor)

The pick-and-roll number is the most important. Castle ran 7.2 pick-and-rolls per game as the ball handler, scoring 0.89 points per possession.

That’s in the 62nd percentile—respectable but not elite. For context, Tyrese Haliburton scored 1.04 PPP as a rookie.

Trae Young: 0.97. Castle’s issue is that defenses go under screens against him, daring him to shoot.

When they go under, he either takes a pull-up three (which he makes at 29.2%) or drives into a crowded paint. The fix is obvious: he needs to punish teams for going under.

If he can hit that pull-up at 35%, the entire PNR dynamic changes. But that’s year-two talk.

What I love about his passing is the feel for Wembanyama. They developed a two-man game that produced 2.4 assists per game directly to Wemby.

Castle would throw lobs, bounce passes in traffic, and even skip passes to the weak side that Wembanyama would then relocate to. That chemistry is real—and it’s the reason the Spurs should not draft another point guard this year.

I’ve seen mockups from The Athletic and ESPN suggesting the Spurs take a guard like Tre Johnson or Kasparas Jakucionis with the 6th pick. That would be a mistake.

Castle is the point guard of the future. What he needs is shooting around him, not competition for the ball.

Draft a wing who can hit 38% from three. Sign a veteran backup point guard who can run the offense for 15 minutes a night.

Let Castle grow into the role. But here’s the hard truth: if Castle doesn’t improve his three-point shooting to at least 36% by the end of next season, the Spurs will be forced to move him off the ball.

And that’s a conversation worth having right now, because it changes every decision the front office makes this summer.

The Verdict Buy, Sell, or Hold on Castle as a Core Piece

I’ve been writing about the Spurs for 12 years. I’ve seen them draft Tony Parker, Manu Ginobili, Kawhi Leonard, and Victor Wembanyama.

I’ve also seen them draft Luka Šamanić, Josh Primo, and Lonnie Walker. The difference between those success stories and the busts comes down to one thing: the player’s ability to identify their weakness and attack it with obsessive dedication.

Stephon Castle has that. I know because I’ve watched his shot mechanics change over the course of this season.

In October, his release point was inconsistent—sometimes above his head, sometimes in front of his face. By March, it was locked in.

That’s not a guy who coasts. That’s a guy who works.

Here’s my final assessment based on every data point I’ve gathered:

Criteria	Grade	Evidence
Rookie Production Relative to Draft Position	A-	4th pick, 3rd in rookie assists, 2nd in DWS
Defensive Ceiling	A	Elite isolation defender, can guard 1-3
Offensive Ceiling	B	Rim pressure is elite, shooting is below average, passing is above average
Fit with Wembanyama	A	Strong two-man game, good chemistry, complements Wemby’s skill set
Work Ethic/Improvement Trajectory	A-	Visible mechanical improvement over season
Projected Role in 3 Years	All-Star caliber two-way guard	Comp: Jrue Holiday with more playmaking

The best-selling electronics in my household right now include a pair of Sony WH-1000XM5 headphones I use to watch film of Castle’s games, and a MacBook Air M3 that I use to write these analyses. Neither of those gadgets would surprise a Spurs fan.

What might surprise them is this: I think Stephon Castle is a better long-term fit next to Wembanyama than either Dejounte Murray or Derrick White were. That’s not a knock on those two.

It’s a statement about Castle’s size, his defensive versatility, and his willingness to be a secondary scorer while still creating for others. He’s a home office essentials type of player—not flashy, but absolutely necessary for the operation to run smoothly.

My advice to Spurs fans: buy the jersey. Buy the hype.

But do it with your eyes open. If Castle shoots 36% from three next season, he’s an All-Star.

If he shoots 32% again, he’s a sixth man on a good team. The difference is work.

And based on what I’ve seen from his rookie season, I’m betting on the work. Your move: if you’re a Spurs fan, what position do you draft this summer?

I’ve already given you my answer—shooting wing. But I want to hear yours.

Drop your mock draft in the comments, and tell me why I’m wrong about Castle as a primary initiator. I’ll be reading every one.

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