Emmerdale spoilers follow.
Bob has been struggling to process the tragic death of his son Heath, who was killed New Year's Day while joyriding with his sister Cathy and Angelica King.
Liam recently connected with the village stalwart in a tender scene, having also lost his daughter Leanna two years ago. Speaking to Inside Soap, McPherson explained how the pair's emotional conversation impacted him.
"At the time, the storylines were elsewhere, so I hadn't worked for about three months, apart from a couple of bits and bobs. So these were the first proper scenes I'd done in a while," he explained.
"I'd started to get a bit low. I've always been like that, even before Emmerdale, when I wasn't working. I'd think to myself: 'Oh, maybe I should just go and run a pub... or be a priest... or a farmer!'"
He continued: "So, doing those lovely scenes with Tony [Audenshaw] and the great crew, which were so well written, was great. I was driving home and I was singing in the car thinking: 'This is fantastic, I just love it.'"
The plot begins as Chas is having a fling with the doctor, who notices a lump in her breast and urges her to make an appointment with her GP.
Speaking recently about the storyline, Emmerdale producer Kate Brooks said: "When this story was first pitched, we were acutely aware how important it was to explore this. With Chas's family history of breast cancer and Chas being such a strong character, and in many ways the bedrock of the Dingles, we wanted to show the impact on not just her, but her immediate family.
"With Lucy Pargeter's innate ability to showcase Chas's vulnerabilities beneath her hardened exterior, we knew she was absolutely the right character to play this with."
Emmerdale airs on weeknights at 7.30pm on ITV1, and streams on ITVX.
If you identify with the themes in this article, the NHS has resources available to help with grief counselling and other support in the UK. In the US, the CDC also has resources available for those grieving.
Emmerdale has worked with Breast Cancer Now on Chas's storyline. In addition to its website, Breast Cancer Now's helpline (0808 800 6000) is open 9am-4pm Monday to Friday and 9am-1pm on Saturday.
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