Despite being the third pick in the 2016 NBA draft, Jaylen Brown still has a lot to learn before he reaches the realm of star in the professional game.
Unlike Ben Simmons and Brandon Ingram who went before him, landing with the Philadelphia 76ers and Los Angeles Lakers respectively, Brown is seen as an investment for the future.
The 19-year-old played in his first preseason game for the league's most successful franchise in history on Thursday, scoring 12 points and pulling down five rebounds in just under 22 minutes on the floor, and the organisation said they are excited by his potential after a strong, athletic display.
However, he still has a lot to be taught and this recent video released from Celtics training shows him being taken to school by former lottery pick Marcus Smart.
The point guard, who has developed into a strong deputy for All-Star Isaiah Thomas, was competing in a game of three-dribble one-on-one with Brown.
After the two had finished bickering over whether the newbie had taken three or four steps on his previous play, Smart cradled the ball between his legs before unleashing to the basket, leaving the teenager with no chance. Of course, he had to tell the whole gym about it.