Wanna mess with a recovering amnesiac’s head? Have her former boyfriend reappear in her life… with a new face!

Samantha Who? producers have tapped Titanic baddie Billy Zane to replace Timothy Olyphant as Sam’s ex, Funk, sources confirm to me exclusively.

But, alas, the recast isn’t part of some elaborate prank being played on Christina Applegate’s memory-challenged alter ego. Rather, Olyphant — who originated the role of Sam’s boss/almost fiancée last April –- was unable to return because he’s now starring on FX’s Damages.

Zane’s recurring stint kicks off in episode 15 when Funk and Sam come face-to-face for the first time since she rejected his marriage proposal.

Is Zane a worthy successor to Olyphant? Or is it just too funky to picture anyone other than the ex-Deadwood sheriff in this role? Sound off in the comments!