It has come to my attention that not only I but a lot of other people accidentally use their league deck for their ranked match or co-op deck for ranked match. I suggest adding a new space for us to save our league deck, and the existing space for everything else - ranked matches and casual games. This would probably be added to the right of our items. I know this would be quite hard to make and accomplish not very much but its just something to consider for the future.
Or that, possibly three little icons of the active deck's characters. Come to think of it, that would be a lot easier to incorporate and would do the same job.