Jaap Stam's team have won their last five home matches and are looking to close the gap on second-placed Newcastle to just three points.
But assistant manager Andries Ulderink has cautioned against complacency ahead of the visit of Ian Holloway's Rangers.
"It would be arrogant and misplaced to think that in any game in the Championship we are going to get three points very easily," Ulderink told the club website.
"We have to work very hard and show some quality on the ball, otherwise a well-organised team like QPR can be very hard to score goals against.
"In the last couple of games they have got some good results - winning at Wolves was a difficult one - so I think their team will have a little bit more confidence than they had five or six weeks ago.
"You see that there is a mentality in that group where they work very hard on the pitch, so it's going to be a very tough game for us."
Holloway has added Kazenga LuaLua to his squad for the short trip along the M4 after signing the winger on loan from leaders Brighton.
"He's someone I've admired for a long time," Holloway said at his pre-match press conference.
"Every time I've seen him I've told him how good he can be. Luckily he wanted to come and play for us.
"He's a very exciting player, and I'm delighted to have him."
Rangers won their last two league matches - after losing the previous six - before a defeat to Blackburn in the FA Cup at the weekend.
Holloway is still keen to add to his squad and has got Brazilian midfielder Sandro off the wage-bill after the 27-year-old joined Turkish side Antalyaspor.
"I've got some other targets we're working on," he said. "But we won't be spending the money that we used to.
"We need youth and experience. We need to get that balance right."