12:06 PM PT -- Brenly has issued an apology to Stroman ... and says he's now looking into sensitivity training after making the du-rag comment.
"During last night's game, I made a poor attempt at humor that was insensitive and wrong," Brenly said. "I apologize to Marcus Stroman and have reached out directly to share those thoughts."
"I have had several conversations with the D-backs and we agree that seeking sensitivity training is an important step so that I can continue to learn from my mistakes in order to be better in the future."
10:52 AM PT -- Stroman's manager, Luis Rojas, clearly has his player's back ... the Mets coach just ripped Brenly's du-rag comment as "very inappropriate."
Luis Rojas on Bob Brenly's comments about Marcus Stroman's durag:
"It's completely inappropriate. I was very disappointed when I heard it. If it was a joke, I didn't get it. That will not help the baseball crowd grow in this game" pic.twitter.com/Y3c9htfhnh
"I was very disappointed when I heard it," Rojas told media members Wednesday morning. "If it was, like, a joke or something, I didn't get it. And, I know a lot of people didn't get it."
Rojas added that, to his knowledge, Brenly has not reached out to him, Stroman, or the Mets to offer an apology or an explanation.
Mets star Marcus Stroman is NOT happy that a quip was made about his du-rag during a TV broadcast Tuesday ... with the pitcher saying the comment had "racist undertones" to it.
The remark went down during the 4th inning of the Diamondbacks' broadcast of the Mets-DBacks game ... when color commentator (and former World Series-winning manager) Bob Brenly threw a jab over Stroman's visible head covering.
And, when Stroman took to Twitter after the game ... he clearly agreed.
The 30-year-old starting pitcher retweeted outrage from several people ... and added in a tweet of his own, "Onward and upward...through all adversity and racist undertones. The climb continues through all!"