Sarah Michelle Gellar "felt protective" over Robin Williams during his mental health struggle.

The 46-year-old actress worked with the late comedian - who tragically took his own life aged 63 in August 2014 - on sitcom 'The Crazy Ones' months before his death, and she tried to look out for him as he battled with depression.

Appearing on the 'Let's Be Clear' podcast, she told host Shannen Doherty: "[I was] one of the few people that knew ... that he was really struggling, that he wasn't well...

"I soaked up every moment I could with him. I felt that the work was the easy part for me.

"It was just making sure that, you know, he was okay and that they weren't working him too hard.”

The 'Buffy the Vampire Slayer' star noted that a "couple of people" working on the show knew about Williams' struggles and were "very protective" of him.

Given the "hard job" and pressures of working on a TV show, they wanted to help the legendary actor "without spilling secrets".

Sarah - who has son Rocky, 11, and daughter Charlotte Grace, 14, with husband Freddie Prinze Jr - had signed on to do the series despite her son being three months old at the time because she wanted to work with Williams.

She explained: "I went back to work right away because I was desperate to work with Robin. When that opportunity came my way, there was no way to pass it up."

After Williams - who, it was later discovered, had been suffering with Lewy body dementia before his death - died, Sarah's priorities shifted as she stepped away from Hollywood to be with her family.

She said: "I just said, 'What am I doing? Like, my kids are really young. I've lived my whole life, I don't want to miss this... I don't want to be gone when Rocky takes this first step'.

"That's what made me take all those years off was Robin. Not just him, but just you know, those moments in your life stop you in your tracks."