Celtics forward Grant Williams walked into the TD Garden Wednesday with a new accessory. On this night, the third-year player was brandishing a “Celtics Pride” towel, showing it off for the cameras.

The Celtics held their fourth annual Pride Night this week, honoring the city’s rich LGBTQ community with pregame and halftime ceremonies. Krystofer Maison, a queer performer and songwriter, sang the national anthem. An LGBTQ youth equal rights advocate, Ava Grant, was presented with the team’s “Hero Among Us” honor.

For Williams, the message of inclusion isn’t abstract or distant. He has several LGBTQ friends, including his best friend Amanda, who is bisexual.

Some of them are fully out, whereas others are more reserved. Williams’ conversations with them over the years have taught him the importance of visibly showing support, such as waving around a Pride rally towel.

“It’s great to empower a community that’s viewed as less so,” he said. “A lot of times, and it’s the same with Black History Month, people question why we have that. It’s something that’s needed, because then it makes you feel comfortable being around it, rather than feeling away from it — rather than feeling like it shouldn’t be a thing.”

It’s easy to be cynical about Pride Nights, and write off the events as just another corporate promotion. On Twitter, some Celtics fans responded negatively to the theme, using the opportunity to heckle the team for its disappointing start to the season.

“Bra just win,” one user wrote.

“Could we get the 6th seed first before doing this,” added another.

But the meaning of Pride Nights goes beyond rainbow-colored seats and trotting out an LGBTQ person to sing the national anthem. They show that LGBTQ people belong in sports, a space that’s historically been exclusionary to our community.

Williams understands the power of that message.

“If a kid can come to a game and see they’re not whatever word they were called in the past, to feel the way that that they feel, to think the way they think, it’s one of those things where naturally they can not only grow and be comfortable with themselves and who they are, but people in the community can embrace them,” he said.

Williams walked into the Garden Wednesday with an excellent accessory.

Jason Collins, who publicly came out as an active NBA player in 2013, played 32 games for the Celtics that season before they traded him to the Nets. At the time, Celtics players rallied around their former teammate, with Hall of Famers Paul Pierce and Kevin Garnett lauding his bravery.

Nine years later, Williams says this group of Celtics would absolutely welcome an out player in their locker room. Bonds between friends are about way more than sexual orientation.

He knows that first hand.

“We’re very embracing of who we are, and people love who they love,” he said. “It’s one of those things where, if you have an out teammate, you embrace him as much as you would if he was straight. We all have things we’re passionate about, and we all have care we want to give. We would embrace them, and we could have conversations where we could maybe educate the people who don’t really know much about the issues.”

When it comes to those conversations, Williams is more than happy to facilitate.