The Danes meet the reigning European champions in the final Champions League group fixture at Stamford Bridge and although Hjulmand believes the West London club will eventually bounce back under the Spaniard, he will be looking to add to the potential boos and jeers he may receive by masterminding a surprise result.
"They have a little dip right now but they'll come back and they'll show who they are in the near future," he said.
"Hopefully not tomorrow but, after that, it's just a matter of time."
Of the expected fan reaction towards Benitez, Hjulmand added: "It is weird.
"The psychology is, of course, to see if we have a result as far as possible. Because that could be an advantage at some point.
"We can only focus on what's important for us and that's what we're going to do on the pitch, no matter what happens outside, no matter what we see or hear.
"This is all about us performing and we have to be very concentrated and play maybe our best match ever to get a result."