For unrated matches, leavers seem to happen almost every other match. Just had another match where I had 2 leavers after the first 2 rounds. So had to play pretty much the entire game 5 v 3. Please add auto fill so at least you can have a full team. I know a complaint would be, "What if all we get are put in matches already in progress?" I feel these 2 options would work.
1) Flag that account who got put in an in progress match so next queue they won't get placed in one.
2) Have a checkbox where you can select willing to auto fill.
I get once ranked/rated or whatever they call it comes out, then yes, auto fill should not happen in those matches. But since this is basically normal matches, something needs to be done here as leavers is already out of hand.