WALTHAM, Mass. – Jaylen Brown has a bright future ahead of him, and not only because of his talent.

Celtics head coach Brad Stevens informed the media Thursday afternoon that Brown is in possession of a key trait that will push him in the right direction throughout his career.

“I thought Joe Johnson taught him quite a bit the other night,” Stevens said with a grin, referring to Johnson, a seven-time All-Star, dropping 17 points Tuesday night on Brown and the Celtics. “And [Brown] was in the weight room yesterday talking about, ‘I need to be in the weight room, because Joe Johnson is strong and hard to guard.’”

That admission didn’t go unnoticed by Stevens.

“You have to look at the game and what you’re doing well and what you’re not doing well, and if you don’t have accountability, you can’t improve,” Stevens added. “How could you possibly get better if you can’t look and say, ‘I need to do this better’? That’s a huge character trait of a really good player, I believe.”

All season long, regardless of his results, Brown has taken note of what he needs to do better.

Just Tuesday night, he put forth one of his best performances of the season. He scored 10 points on 4-of-6 shooting against the Jazz, marking his sixth double-digit scoring effort of the season. He also grabbed three boards, dished out an assist and grabbed a steal during only 13 minutes of action.

Yet there he was, standing in the weight room with his coaches the following day, admitting to all who could hear him that he was out-muscled by the 35-year-old Johnson.

It was no surprise, then, to find Brown working hard with the strength and conditioning staff ahead of Thursday’s practice.

As Stevens spoke about the rookie to the media, Brown ironically stood about 10 feet away, perpendicular to the padded wall along the baseline of the practice court. He continually fired a padded, 37 1/2-pound Dynamax medicine ball into the wall, first working the upper-left side of his core, and then the upper-right side, all before repeating the exercises for his lower core.

Less than two days after learning from Johnson that he needed to add strength in order to become the player he wants to become, Brown was putting in the work to do exactly that.

Johnson wasn’t the first opponent to play the role of teacher for the 19-year-old Brown. Following a preseason game against the Knicks at Madison Square Garden, Brown commented that “it was an educational experience” defending one of his idols, Carmelo Anthony. Brown took the lessons he learned that night at the defensive end and transferred them into his memory bank as he prepared for his first NBA season.

All of the lessons Brown has learned have helped him to improve as the season has progressed. His scoring and efficiency has improved with each month of the season, and he is becoming a better defender each and every time he steps onto the floor.

This is due in large part to Brown’s pure ability, but it is also due to his willingness to self-examine.

It’s not every day that you hear an NBA player admit that he was outmatched by an opponent, but Brown has shown both privately and publicly that his ego is not too big to confess such feelings. That’s a character trait that will fuel a successful career.