I mean, if the defense puts on its own case, and they don’t call Manifort as a part of it, then the jury will wonder (in spite of jury instructions to the contrary) why Manifort is not called as a witness? They will wonder “what is Manifort hiding?” Put on a case and call Manifort, and the prosecution will murder him.
Looks more like they are not putting on a defense because they don't have one to put on.
No defense, no witnesses and won't call Manifort himself for obvious reasons.
After being found guilty he tries to convince Trump that he better be pardoned.
Maybe he can get a hung jury if lucky.