"The Oakland A's pride ourselves on being inclusive," the team said in a statement. "We respect and support all of our players' constitutional rights and freedom of expression."
Maxwell later offered extended thoughts on his decision, which were relayed by Lee:
MLB also released a statement, per ESPN:
"Major League Baseball has a longstanding tradition of honoring our nation prior to the start of our games. We also respect that each of our players is an individual with his own background, perspectives and opinions. We believe that our game will continue to bring our fans, their communities and our players together."
Earlier Saturday, Maxwell hinted at kneeling with a post on Twitter:
According to the Dallas Morning News' Evan Grant, Maxwell is the son of a United States soldier and was born on an army base.
Maxwell's decision comes one day after President Donald Trump said at a rally in Alabama that he would like to see NFL owners cut players who protest social injustice during the national anthem.
"Wouldn't you love to see one of these NFL owners, when somebody disrespects our flag, to say, 'Get that son of a bitch off the field right now, out, he's fired. He's fired,'" Trump said, per CNN's Brian Stelter. "You know, some owner is going to do that. He's going to say, 'That guy that disrespects our flag, he's fired.' And that owner, they don't know it [but] they'll be the most popular person in this country."
Trump also implied in a tweet Saturday that the Golden State Warriors wouldn't be invited to the White House after Stephen Curry said he would advocate for the team not to visit.
"I don't want to go," Curry said Friday, according to USA Today's Sam Amick. "That's kind of the nucleus of my belief...(But) it's not just me going to the White House. If it was, this would be a pretty short conversation."