Collymore says Villa fans won't be excited about the Frenchman's arrival.
The former Aston Villa and Liverpool striker told talkSPORT: "If it was a manager that was looking to build the club and take it on from three sixth-placed finishes with Martin O'Neill surely you'd give him longer than two years.
"[An interim manager is] what Randy Lerner and Paul Faulkner are viewing it as.
"It's almost a kind of trial.
"If he needs to have a trial then it doesn't send to me, as an Aston Villa supporter, a very positive sign."
Although Collymore didn't play under Houllier at Liverpool, the much maligned football pundit has been critical of the Frenchman in the past, and in particular his transfer dealings.
He continued: "You can almost break Gerard Houllier's English career into two parts, before his heart problems and after.
"Before his heart problems [Liverpool] won the treble, and then he was out for five months and failed to finish in the Champions League. He spent a lot of dough on people like El Hadji Diouf, Salif Diao, Bruno Cheyrou and lots of people from France.
"The worry for me is that Aston Villa have a really good British-based first team and academy."