The Cottagers are three points from safety.
Parker said, “It's a must-win game, but last week was a must-win, next week is a must-win. We're at seven games to go and everything is a must-win.
“We're going to fight, scrap do everything in our power to stay in this division this year. I'm relishing that [challenge] and I can't wait for Friday.
"While I've been pleased with how the team have progressed and how the team are doing, I also understand that what would be successful for this team this year is staying in this division."
Fulham striker Aleksandar Mitrovic opened the scoring at Aston Villa on Sunday with his first goal for the Cottagers since September, after scoring five in three games for Serbia during the international break.
“He chose a really good time [to find form]," said Parker. "He looks every bit of that - sharp, a real buzz about him. Sometimes as players you need some time away, and to get that spark back. He has a massive part to play this season."