For all you new guys - just so you know - around this time of year we add Keepers, we have the supplemental, and trades firing off left and right. I don't enforce the minor/major league roster limits during this time. Check my roster for example - I have 17 players in the minors.
After the Supplemental I'll announce when it's "roster cleanup time" - so don't worry about posting transactions to move players up and down to meet the roster limits for now - just know that you can't exceed the total roster limit of 45 players.