Samba agreed to take a huge drop on his £120,000-a-week wages at Anzhi Makhachkala. Yet his 4½-year deal with Rangers is still believed to be worth around a whopping £18m - earning him £77,000 a week.
He told The Sun: "Van Persie is an excellent player but I've been working on my fitness and I'm really much fitter than I was for the last game at Swansea.
"So it will be more difficult to beat me.
"He is on fire but I am positive I can have a good game against him - although it is not only him we have to stop because United have a lot of top players.
"They will win the Premier League this year but they are coming to QPR and we need the points more.
"When you play against top teams, you need to be on top of your game. We have everyone pointing in the same direction and we need to put that into practice out on the pitch."