The trial of a schizophrenic who admittedly murdered a beloved Upper East Side psychiatrist has been delayed until at least Monday afternoon amid concerns about the defendant’s mental fitness to proceed.

Manhattan Supreme Court Justice Edward McLaughlin yesterday called a halt to the final day of jury selection in the case, ordering killer David Tarloff to undergo a psychiatric evaluation Monday morning. Yesterday, Tarloff refused to leave his jail cell.

He is seeking to be found not guilty by reason of insanity in the 2008 meat-cleaver slaying of Dr. Kathryn Faughey.