Kaley Cuoco’s Terrifying Snub from A-List Star

'Rose maybe not as happy. I don't know. I don't know,' Cuoco said of McGowan. 'I still don't know if she liked me. I don't know. But Alyssa was amazing. I was terrified.'

Cuoco noted that joining a long-running series midstream can feel deeply awkward.

'It's a weird thing coming into a show with how many years. I was year eight. And I only did the one season,' she explained. 'It's walking into someone's family dinner. It's so weird.'

She later carried that awareness with her when she starred on The Big Bang Theory for 12 seasons.

'I think about that with Big Bang … We were on that show for 12 years. It's a weird - you know each other so well. So anyone that came in, I was very aware of like, this must be so weird for you,' she said. 'I always remembered that from Alyssa.'

The Daily Mail has reached out to McGowan's representatives for comment, but has not heard back, at this time. 

Charmed originally premiered on The WB in October 1998 and followed three magical sisters navigating supernatural threats.   

Milano starred alongside Holly Marie Combs and Shannen Doherty, who exited after Season 3 amid reports of on-set tension.

McGowan later joined the series in Season 4 as Paige Matthews. 

Cuoco ultimately joined the series in 2005 as Billie Jenkins for its eighth and final season.

Over the weekend, Cuoco looked back on her time on Charmed, which she admitted was 'intense and difficult.' 

'I came into Charmed really not thinking anything other than I got this cool job,' she said. 'But it caused a few more waves than I imagined. Let me put it this way: from that point on, no matter what job I have, I am so understanding of new people coming in - whether that’s people behind the camera, or on camera, someone with one line.'

While going into more detail about her experience, Cuoco said 'there were a few people on that show that were wonderful to me, and there were a few people that weren’t.' 

'I remember them both very clearly. I’ve been doing this my whole life, and I have had very few experiences that weren’t the best, but I remember thinking: "I will always make sure every single person feels like they’re part of the group." Because there’s nothing worse than feeling outside of it, especially on a set when everyone is cliquey and has been together for so long, and there’s a comfort level. When someone new comes into that, it’s tough,' she said.