4:44-mark here:
https://www.youtube.com/watch?time_c...&v=6vEMZmX3MKU
Narrator: "For her, the Rumours lineup of the band had been its high point."
Stevie: "It’s just not replaceable, you know? Mick can go on forever and ever trying to replace it, but he can’t. It never will happen – ever. So I just didn’t want to go through the grief of trying to create something out of something that had already been – and had already been about as big as you can get."