Boston Celtics swingman Jaylen Brown is finding motivation in the words of critics who claim that he has already reached his peak.

During his media availability on Thursday, Brown made it clear that he hasn't reached his ceiling yet:

“I have no doubt in my mind that I can play basketball,” Brown said, via Chris Forsberg of NBC Sports Boston. “I don’t doubt myself at all. As soon as you let doubt creep in, you’re done. I don’t have any doubt. … I didn’t peak in my 2nd year.”

Brown, who's entering the final year of his rookie contract, has become an important piece of Boston's rotation. At 6-7 and 220 pounds, he can guard a variety of positions. However, it's also his ability to create his own shot that causes problems for opposing sides.

In his 74 appearances with the Celtics last regular season (25 starts), Brown racked up averages of 13.0 points on 46.5 percent shooting from the field (34.4 percent from beyond the arc), 4.2 rebounds, 1.4 assists and just under one steal (0.9) in 25.9 minutes per outing.

Brown has changed his image a bit for this season. Gone are the days of his signature flat-top. Enter a new era of faded buzz cut:

The Celtics finished the 2018-19 regular season with a 49-33 overall record, which earned the team a No. 4 seed in the Eastern Conference. Unfortunately, Boston was defeated by the Milwaukee Bucks in the second round, 4-1.