"Tough day," Bryant wrote. "I've seen coaches as well as friends come and go. No matter how many years I've been playing, it's still hard to deal with.
"I had a good relationship with Mike and I will continue to have one. I wish him and his family nothing but the best. I spoke with him today and thanked him for all of his hard work and sacrifice.
"As a team, we must focus our energy on tonight's game. We must block out the weight of today's news and simply do our jobs to the best of our ability.
"I'm not sure what direction we are heading in next. All I can do is focus on the here and now. Mamba out."
Bryant has staunchly stood behind Brown despite the team's poor start.
At Thursday's practice, Bryant dismissed claims that he held Brown in contempt after a video went viral on YouTube in which the Lakers star stares down Brown during Wednesday's 95-86 loss to Utah.
"I've been his biggest supporter," Bryant said.