Sienna Miller thinks it’s “astounding” Chadwick Boseman was able to make ’21 Bridges’ while battling cancer.

Sienna Miller

Sienna Miller

The 39-year-old actress “would never have known” her co-star – who died last summer – was ill when they were shooting the movie in 2018, but with hindsight she can understand why he was so thin and tired, and she recalled how they said a “real goodbye” at the end of filming.

In an interview with The Sunday Times Culture magazine, she said: “I would never have known he was sick to the degree he was. But I could tell he was really tired in a way that now makes sense.

“It never affected the work. But he was very thin. Thinner when we went back to reshoot.

“It is astounding he was at that stage of a battle and we made that film. I remember when I said goodbye, the last time I saw him.

“In reflection, which is often the case, it felt like a real goodbye. And I remember being really moved, but also really confused.

“He had tears in his eyes and it was a hug and I felt it was the sweetest thing ever, and never saw him again. But it makes sense of course. You put the pieces together in the aftermath.”

Sienna previously told how Chadwick had given up some of his own salary to ensure she was better paid for the movie and she’s vowed to now always fight for her worth as she’d be “embarrassed” for his gesture to have been in vain.

She said: “For many years I underestimated myself to such a degree I would’ve accepted anything.

“But Chadwick’s gesture and the way women in my industry are talking about [pay] is empowering. I’d feel embarrassed now to not fight for myself.

“But it can take me being put into that corner to do something.”

The ‘Wander Darkly’ actress wants to keep working for as long as she can.

She exclaimed: “I want to be doing this when I’m 80. Like Glenda Jackson playing King Lear!

“My goal is to be hired by Paul Thomas Anderson and be the lead. Or Scorsese.”