Chad Ford often has a good feel for what Danny Ainge is thinking and wrote the following thoughts on Tyreke Evans. Note: this is probably a lot more speculation than rumor.
[The Kings] should've never drafted him. At the time GM Geoff Petrie was trying to save his job and wanted a guy who could come in and play right away. A few years later, it's pretty clear that Evans peaked in his rookie year. The Kings are a mess and Evans' style of play doesn't help things, and, again, his stock is so low, I'm not sure what the value will be. One team to watch is the Celtics -- Danny Ainge loved him before the draft. I'm not sure Boston has the assets to get a deal done, but I could see the Celtics trying to make something happen.
Evans does have some star potential that he hasn't lived up to. So that makes him just the kind of guy that Danny Ainge might try to buy low on. That said, he's not exactly what this team needs right now and will likely cost some valuable chips to acquire. So take with a grain of salt.