The Frenchman scored 24 goals in 82 appearances for the Reds during a two-year spell at the Merseyside outfit after being signed in a £14m deal in 2004.
The 31-year-old has scored four goals in all competitions this season, and Liverpool assistant manager Pascoe expects Cissé to be desperate to score against his former club.
“Any player playing against his former club always has the incentive to do well,” Pascoe told Liverpool’s website.
“They want to show what the other club is missing. Cissé’s a big threat and we have to make sure that we stop the threat of his power and his abilities both in the air and on the ground.
“But with the way that QPR are playing at the moment under Harry – it won’t just be Cissé, the whole team will be a threat.”
But despite a dip in form, Pascoe expects the Hoops boss to use all his man-management skills and have his struggling squad fully motivated on Sunday.
“QPR will be a threat because of their new manager,” he added.
“Any new manager coming in always gives the team a boost and given Harry’s levels of man-management, I’m sure that they will pick up their form.
“He’s a motivator. I’ve watched QPR over the season and they were a little unlucky when Mark Hughes was their manager. They were playing well but they just weren’t converting chances.
“They have got a good squad there and I’m sure they will do well and they will improve.”