He apparently, auditioned (https://www.yorkdispatch.com/story/entertainment/2021/05/31/gavin-macleod-mary-tyler-moore-love-boat-dies/116706524/) and basically got the part (https://www.metv.com/stories/part-two-of-our-interview-with-gavin-macleod) of Lou Grant (https://books.google.com/books?id=3vNMxIzSFnYC&pg=PA21&lpg=PA21&dq=Gavin+MacLeod+Lou+Grant&source=bl&ots=OhdnA-iDK5&sig=ACfU3U12XcG5FIk2-esiuQPd18Piugov7A&hl=en&sa=X&ved=2ahUKEwiTsp_Zp86HAxVaJUQIHakcEag4FBDoAXoECCUQAw). But he wanted to read for Murray, which was then a different role. Murray was supposed to be the antagonist and office enemy of Mary Richards. It took them so long to cast Lou Grant at one point they asked Gavin again if he'd do it and he declined. Ultimately, they softened Murray up (after the first run though pilot which got bad audience reviews) and then redirected Murray's antagonism away from Mary towards Ted Baxter.