Wenger, who in great contrast to Houllier sits proudly on top of the Premiership table, believes that his close friend has been unfairly victimised by a growing number of critics in recent months.
Wenger said: "Who would love to see their friend victimised, so of course I feel sympathy for him. I know how fragile it is.
"His team has been really unlucky this year – and like always when things don’t go for you then you get the stick.
"It shows the strength of a club that when things don’t go well everyone is still behind you. Then it is down to the board to support the manager."