I don't know about Mayo or Morrow, but I think one of the few ways to try to salvage the season would be to try to make a lateral move of some sort to get more offensive talent on the roster.
The biggest problem with the Celtics as currently constructed is they're still built as if the Big 3 are going to do most of the scoring. That hasn't been a consistently viable game plan against good teams for a while now. Even last year the C's depended a great deal on Shaq and later Glen Davis for offense. We're not going to get 60+ points from the Big 3 alone anymore.
This year, Brandon Bass has operated as our de-facto 2nd or 3rd option on offense. It's no wonder we're struggling.