Jaylen Brown fires back at Stephen A. Smith after ESPN man read anonymous text criticizing Celtics star's attitude: 'State your source'

Boston Celtics star Jaylen Brown is calling out Stephen A. Smith - telling him to reveal his sources after the ESPN analyst brought up an issue with the NBA star's attitude.

On an episode of 'First Take' last week, Smith red a text message on the show from someone he described as an 'NBA source'.

'It's not so much that he's underrated, it's just that he's not liked because of his I-am-better-than attitude,' Smith said, reading off the text message.

'He knows it. It's the same reason that he is not as marketable as he should be,' Smith said before adding - 'That's what an NBA source just sent me.'

Brown clearly saw the clip calling him out and challenged Smith on Twitter to 'State your source'. 

NBA legend and Hall of Famer Isiah Thomas also responded on X to the ESPN man.

'I have been a friend, mentor and advisor to @FCHWPO [Brown] since he was a student at UC Berkeley he is 100 percent marketable and before you slander his name @stephenasmith tell your source to put their name on it or don't speak on it. Let it be known.'

Brown's reputation has been questioned in the past and the Celtics star has been quick to call out anonymous sources before.

Back in 2016, in the leadup to the NBA Draft, a nameless NBA executive told Andscape that Brown was 'too smart for the league'. 

Brown didn't hire an agent going into the draft, instead leaning on Thomas as a mentor.

'I am who I am. Take it or leave it,' Brown said after the report from Andscape came out. 'I'm not going to change my values and change my approach because someone feels uncomfortable. 

'I am not going to be disrespectful or step on any toes. But I am going to be me.'

'It's not malicious,' the Andscape report continued. 'He just wants to know what is going on. Old-school coaches don't want guys that question stuff.'

Brown questioned that report once again in 2018 when asked about it at the league's Rising Stars Challenge.

'What is the so-called mold of a basketball player?' Brown contested in Feb. 2018, via Boston.com. 'I challenge whoever has the ideal or the ideology of a 'so-called basketball player,' I challenge them to come out and say what that is.'