Like Fernandez, Barbosa not so much.
We need a backup for Pierce, and Fernandez would be able to fill that role, while Barbosa can't. We could re-sign TA , which would give us a back court bench of Fernandez, TA, and Bradley. That would be a very versatile backcourt.
I'm not sure how Przybilla's knee rehab is progressing, but if he's healthy, he would be a great addition. He is a legit 7', plays solid "D", and rebounds very well.
I do believe a trade involving Sheed, Lafayette, & Gaffney for Przybilla & Fernandez does work money wise. If Portland is simply looking to shed salary, this would be a good deal for them. So long as Sheed retires (no buy-out), along with Lafayette & Gaffney's unguaranteed contracts, Portland would be able to clear all salary from their books.