The 28-year-old completed his move from Newcastle to west London yesterday, penning a four-year deal at Loftus Road.
Barton pronounced himself fit and available for Saturday's clash at the DW Stadium upon signing, but it now appears he was not registered in time for the game.
As a result, the midfielder's QPR debut is likely to come in two weeks against former club Newcastle, which Barton knows will be a difficult experience.
Joey Barton: "There is an important game at Wigan first and foremost then we will start concentrating on the Newcastle game after that.
"It will be strange. I have still got a lot of friends at the football club and spent four and a half happy years there.
"It will be difficult but that is football.
"Ships in the night, that is the philosophy we live by and that is a prime example of it."