... why is Rosenthal talking about this like the D-Backs can just pull Davis back? Trade waivers are revocable. I think a lot of confusion about waivers is that there are multiple types of waivers, some revocable some not. Trade Waivers -- These are in place to basically keep teams from majorly rearranging their rosters during the playoffs -- This gives leverage to teams over other teams. These are revocable. It's basically a tool to "keep people honest" Outright Waivers -- These are really in place to give players some leverage over their career. If a team wants to send a player to the minors, but move them off the 40man, they have to be exposed to irrevocable outright waivers. This allows teams to pick up players that may be blocked, and allow some player movement. When the Brewers sent Turnbow down to AAA the last time, he was exposed to these waivers, no one claimed him, and he was allowed to pitch at Nash., but not be on the 40man. Unconditional Release Waivers -- These waivers are what Bill Hall will be on, if he is not already. This is for players the team wants to cut ties with. Whether they are revocable or irrevocable is moot -- Of course a player is usually DFA'd first, and then if no one shows an interest in trading for him -- they are given their release. Optional Waivers -- These are revocable as well -- These usually happen at the start of the season and are mostly a formality -- These are used if a player has an option, but they have been in MLB for 2-3+ straight seasons, when the Brewers sent Bush down last season he had to clear these.