LeBron James Coaches Bronny During Lakers Vs. Suns Game

LeBron James isn't just Bronny 's dad and teammate, he also acted as his coach on Thursday ... giving the Lakers rookie some sound advice during their game against the Suns.

The moment happened during the preseason matchup at the Footprint Center in Phoenix ... where Bronny played 17 minutes in the overtime win.

At one point in the contest, LeBron -- who didn't suit up for the tilt -- was talking up the 20-year-old guard near the bench ... and the TV broadcast zoomed in to catch the conversation.

No word on what King James said during the interaction, but Bronny ended up with four points and two rebounds ... as well as a career-first flagrant 1 call against Jalen Bridges .

The Lakers ultimately won, 128-122.

Lakers head coach J.J. Redick explained why 39-year-old LeBron didn't play ... joking, "DNP -- Old ... Taking it out of [Gregg Popovich's] book."

He'll also miss the final preseason game against the Golden State Warriors on Friday.

Coaching up his teammates is nothing new ... as Bron shares his hoops knowledge with his squad on a regular basis.

The four-time NBA champ will do it again on Oct. 22 when the Lakers face the Minnesota Timberwolves -- the first game of the regular season.

And most likely, he'll share the court with his son (in a game that matters) for the very first time.