Canonical pushState URL?

I've got a large page with several sections on it - should be individual pages, but they're not - can't do anything about that for now. Used history.pushState to give them unique URLs and refine targeting - can I use canonicals on the pushState URLs?

I use a canonical on the main page, but when I check in Webmaster, its showing me all the pushState URLs without return tags. Should I care?