Sarah Michelle Gellar Says She's 'Never Been So Proud' of Selma Blair After DWTS Farewell

Andrew Eccles/abc Selma Blair and Sasha Farber

Sarah Michelle Gellar is one proud BFF!

On Monday night, the Cruel Intentions alum, 45, reflected on her longtime friend Selma Blair's surprise announcement to step away from Dancing with the Stars in an emotional Instagram post.

"Long before @dancingwiththestars I knew you were a ten, and now the world knows," Gellar, 45, wrote, alongside a photo of the two actresses. "Selma I've never been so proud of you (and I'm often proud of you) You make the rest of us believe that we can do anything. That we can never give up."

The 50-year-old actress, who was diagnosed with multiple sclerosis in 2018, announced her decision to bow out of the dance competition to take care of her body on Monday.

"You know I've been monitored and in touch with my doctors this whole process," Blair told her partner Sasha Farber in a pre-taped package. "I had these MRIs and when the results came back, it just all adds up to I can't. I can't. I can't go on with the competition. I pushed as far as I could."

RELATED: Selma Blair Drops Out of Dancing with the Stars Season 31 Due to MS Concerns: 'I Can't Go On'

Sarah Michelle Gellar Instagram

RELATED: Sarah Michelle Gellar and Selma Blair's Friendship Photos Through the Years

Gellar concluded her post by thanking Farber for being her friend's partner, writing "I will miss getting to watch the happiness radiate from Selma each week as she stepped on stage with you."

"Thank you for that gift. And speaking of gifts- @selmablair your love and friendship is the greatest gift. I love you Blair," she added.

For more on Selma Blair, listen below to our daily podcast PEOPLE Every Day.

In September the Buffy the Vampire Slayer alum told PEOPLE exclusively before the season began that she was "of course" excited to see Blair compete on the reality competition series — and promised she would "be begging" for votes on her friend of nearly 25 years' behalf.

"What's the word when you're like, 'I'll be out there looking for votes for her?'" Gellar said at the time. "Shilling — shilling for votes. That was what it was!"

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human-interest stories.

Eric McCandless/ABC Selma Blair on DWTS

RELATED: Selma Blair 'So Proud' of Her Strength in 'DWTS' Performance amid Multiple Sclerosis Journey

The actress was in attendance last month during another special night in the ballroom in which Blair performed on Elvis Night — and even did a cartwheel during her dance!

After her performance, Blair was ecstatic that she got to share the evening with Gellar.

"First of all, to be dancing to Elvis, to keep a smile on my face because I genuinely am so happy, and have Sarah here who's been with me from my first-ever movie in Hollywood," the actress said to reporters after the show.

"And [for Gellar] to come to something like this 25 years later and give me love, I mean we're best friends, but to work out with her schedule and everything, and to have Sasha who's so wonderfully teaching me art of a better balance, it's all glorious to me."

Dancing with the Stars airs Mondays at 8 p.m. ET on Disney+.