The Baggies have won just three of their last 13 games and just one of their last seven.
But it was the manner of last night's loss that was particularly alarming with Ismael's men failing to do the basics and lacking any sort of passion or desire.
That performance followed a falling out between the boss and goalkeeper Sam Johnstone earlier in the day that led to the England international being omitted from the squad.
Ismael was appointed in the summer on a four year deal with the aim of implementing his philosophy and giving the club a new identity.
The boss has said on many occasions that will take time – with the Frenchman believed to feel he needs three or four transfer windows to get a squad truly in his mould.
But fans are angry after last night's performance and Albion's performances in general this season – with thousands walking out the stadium last night after Preston took a 2-0 lead.
So do you believe Ismael should stay or go? Tell us what you think by voting in the poll.