Later Friday, San Antonio Spurs coach Gregg Popovich and assistant Becky Hammon also stood during the anthem before their game against the Sacramento Kings. In the league's two previous games Thursday -- Jazz-Pelicans and Clippers-Lakers -- all players and coaches kneeled during the anthem.
After the Magic's victory, Isaac, who is Black, was asked if he believed that Black lives matter.
"Absolutely," Isaac said. "I believe that Black lives matter. A lot went into my decision and part of it is my thought that kneeling while wearing a Black Lives Matter T-shirt don't go hand in hand with supporting Black lives. And so I felt like, just me personally and what it is that I believe in, standing on a stance that I do believe that Black lives matter, but I just felt like it was a decision that I had to make and I didn't feel like putting that shirt on went hand in hand with supporting Black lives."
Isaac, who became an ordained minister in March, discussed his faith several times while describing why he made his decision.
"I don't think that kneeling or putting on a T-shirt for me, personally, is the answer," he said. "I feel like for me Black lives are supported through the Gospel. All lives are supported through the Gospel. That we all have things that we do wrong and sometimes it gets into a place of pointing fingers about which wrong is worse.
"I feel like the Bible tells us we all fall short of God's glory and at the end of the day whoever will humble themselves and seek God and repent of their sins that we could see it in a different light -- see our mistakes and people's mistakes in a different light, see people's evil in a different light. And that it would help bring us closer together and get past anything that's on the surface that doesn't really deal with the hearts of men and women."
Isaac, 22, also said he spoke to his teammates in a team meeting prior to Friday's game.
"We had a team meeting," he said. "I told them that they know who I am as a man, they know who I am as a person. They know what it is that I believe and they respected me for the decision that I made and it was all love. So they understood that for me personally it's not coming from a position of wanting to be popular or seen or anything other than a humble [servant] of Jesus. And that's where I stake my flag and that's just how I felt and they respected me for it because they know who I am, they know my heart."
When asked if Isaac explained his decision, veteran swingman Evan Fournier said that Isaac hadn't fully explained what he would do, but his teammates supported him either way.
"To be honest, he don't need to," Fournier said. "That's his choice. We all decided that we was going to kneel, but his choice was not to kneel. That's his choice. There was no pressure from any of us to do anything. And we support him, period."
Magic coach Steve Clifford echoed a similar sentiment.
"We talked, and I think every team probably had the same conversation -- that's a personal decision," Clifford said. "We're all supporting each other in this. And if guys are not comfortable kneeling and they want to stand, then nobody has a problem with that; I support him, his teammates support him, the organization supports him, so that's part of living in our country."
Clifford added on Saturday the he is confident that Isaac will be able to handle whatever criticism may come his way.
"He's going to get the support from everybody; we all support him," Clifford said Saturday. "He's a special person, and he has the mental makeup to be able to handle this."
Nets players and coaches also supported Isaac's decision to stand for the anthem. Veteran Nets swingman Garrett Temple said he didn't see Isaac standing but reiterated that Isaac has the ability to stand up for what he believes in.
"People protest in their own way," Temple said. "If somebody believes that isn't the way they want to protest, then they don't do it. At the end of the day, I don't have a problem with what Jonathan did. I only have a problem with it if he says, 'Black lives don't matter,' or he disagrees with what we're fighting for. But I think, knowing him the little that I do, I think that he agrees with what we are trying to accomplish here in America, in terms of trying to confront and get in front of racial injustice and help our people that have been marginalized for so long. So I have no problem with how he protests, what he thinks about other people's protests. There's a lot of different ways to skin a cat. If that's his reason, good for him."
Isaac, who scored 16 points in 16 minutes in his first game back since injuring his knee in January, also defended his decision not to wear a Black Lives Matter T-shirt or sport a social justice message on the back of his jersey.
"People have opinions and people have the way that they feel," Isaac said. "So obviously, me not wearing [a Black Lives Matter shirt], people are going to take it in a million different places. That's what I saw it for myself. It was just something I didn't feel went hand in hand with supporting Black lives. It's just a means to an end. We're protesting and we're doing things to get something done, and I'm standing and not wearing a T-shirt to get something done as well."
The NBA has had a rule since the early 1980s saying players must stand for the anthem. But commissioner Adam Silver said Thursday night, when players from New Orleans, Utah, the Lakers and the Clippers all kneeled for the anthem, that he was relaxing that policy in these times when a desire for equality and social justice is at the forefront of many conversations in the U.S.
Popovich declined to explain his decision to stand Friday.
"I prefer to keep that to myself," he said after the Spurs' 129-120 win. "Everybody has to make a personal decision. The league has been great about that. Everybody has the freedom to react any way that they want. For whatever reasons that I have, I reacted the way I wanted to."
In another Friday game, all players and coaches for the Celtics and Bucks kneeled during the anthem, as did two of the referees, James Capers and Kevin Scott. The third, Brent Barnaky, stood with his hand on his heart and his head bowed.
"I fully support the social justice movement and everyone who chooses to kneel as a means of peaceful protest," Barnaky said in a statement to ESPN explaining his decision. "For me personally, it's important I stand for our national anthem, which is what I chose to do this evening. I believe you can be committed to both ideas, and I will continue to support the league's social justice efforts to help bring equality to this country."
ESPN's Tim Bontemps and The Associated Press contributed to this report.