I think AA is taking a wait and see approach because there's a lot of question marks in spring training in regards to the 5th starter/pen (Delabar, Norris, Estrada, etc.) and also the bench guys (Dirks, Izturis, Travis, etc.)
Maybe he'll spend a bit more after the dust settles there or wait til mid season to address a glaring weakness via a trade where he can take on salary. He should have the flexibility to do so if needed this year, especially if a lot of things break right for him in ST.