Here's something I do that makes my AAA team better but serves a BL purpose. After the 8th spring training game and the next half cycle, FA drop their demands to one year. I seek out injury replacements players, with options, to stash in AAA. They're usually 1-1.5m for one year. They make my AAA team competitive and, if there's a BL injury, I have a replacement already making BL money. If there is no injury, they're still good roster expansion call-ups.