What are the penalties for leaving a game early? QM or HL
It looks like the game places you into a deserter queue. The deserter queue means you must play with other players who have similarly left the game early and is not available for Hero League.
Since I left 1 game early it looks like I am only required 1 deserter game. I will update this if I find more information.
In Hero League, you lose 300 points, dropping you 1 full rank from where you were. In addition to this penalty, you are required to play a quick match before you are allowed to play Hero League again.