The woodwork was the winner of the afternoon and after a second half downpour the Millers gained their point needed at the start of play to seal at least fifth spot with Aldershot playing Morecambe on the final day.
Nicky Law came closest to opening the scoring when he headed against the bar from Gavin Gunning's cross from the left.
Clayton Donaldson also smashed the bar at the other end for Alex as his fierce shot bounced down and out of the goalmouth and he also scuffed an effort past the upright.
Andy Warrington was called into action to tip a Murphy header away to safety shortly afterwards.
After the break the Millers shook things up with two changes, but Calvin Zola missed the best chance of the period just after the hour as he shot over the top from Donaldson's pull back.
With top scorer Adam Le Fondre relatively quiet, Drewe Broughton could have sealed the points but he seemed to lose his footing when shooting past the post after Matt Tootle's backpass fell straight to him as honours ended even on an uninspiring afternoon.