Sarah Michelle Gellar shared a throwback photo of her and Nicholas Brendon following the “Buffy the Vampire Slayer” alum’s death at age 54.

On Saturday, the actress, who starred as the iconic Buffy Summers on the hit series, took to Instagram to pen a heartfelt goodbye to the actor, who played the lovable Xander Harris.

“‘They’ll never know how tough it is to be the one who isn’t chosen,'” Gellar began in her Instagram Post on Saturday, quoting Brendon’s character. “‘To live so near to the spotlight, and never step in it. But I know. I see more than anybody realizes, because nobody’s watching me.'”

She added, “I saw you Nicky. I know you are at peace, in that big rocking chair in the sky.”

Co-star Alyson Hannigan, who played Willow Rosenberg, also posted a heartbreaking message.

“My Sweet Nicky, thank you for years of laughter, love and Dodgers,” she captioned the shot of a Season 6 still from the series. “I will think of you every time I see a rocking chair.  I love you. RIP 💔😢”

Caulfield, who played Brendon’s love interest Anya on the show, wrote on her stories that she has “no words yet,” while David Boreanaz, who portrayed the beloved vampire Angel, reflected on their time together.

“Some people leave a mark without trying,” the “Bones” alum wrote in part on Instagram.

Brendon starred in the vampire series alongside Gellar, Hannigan, Caulfield, Boreanaz, Charisma Carpenter, Seth Green and Anthony Stewart Head from 1997 to 2003.

The actor’s death was announced by family in a social media statement on Friday.

“We are heartbroken to share the passing of our brother and son, Nicholas Brendon,” the statement read. “He passed in his sleep of natural causes. Most people know Nicky for his work as an actor and for the characters he brought to life over the years.”

“In recent years Nicky has found his passion in painting and art. Nicky loved to share his enthusiastic talent with his family, friends and fans,” it continued.

“He was passionate, sensitive, and endlessly driven to create. Those who truly knew him understood that his art was one of the purest reflections of who he was.”

“While it’s no secret that Nicholas had struggles in the past, he was on medications and treatment to manage his diagnosis and he was optimistic about the future at the time of his passing.”

The message concluded by asking the public for privacy as the ’90s star’s surviving family members “grieve his loss and celebrate the life of a man who lived with intensity, imagination, and heart.”

In 2022, Brendon revealed he experienced a heart attack and was diagnosed with a congenital heart defect.

The actor also battled cauda equina syndrome, for which he underwent multiple spinal surgeries. 

In a 2017 interview with The A.V. Club, Brendon said “‘Buffy the Vampire Slayer,’ however, just felt like it was some sort of blessed, ordained project.”

“There were so many times I’d just be on set and in this place of wonder, saying, ‘Oh my god. I can’t believe I’m a part of this show,’” he reflected. “It was like a dream.”

However, less than a week before he died, Brendon took a swipe at Gellar in a Facebook Live.

“I believe that the way that the show ended shouldn’t have ended the way that it did,” he told fans on March 14.

“Sarah… she worked really hard but she sort of f–ked the show, in a way. She told everyone she was leaving way too late into the series, so [creator] Joss [Whedon] was not prepared for that,” he continued. “You have an arc every season… it wasn’t fair to the crew, the cast or the show.”