Barton was on loan at Marseille last season and had made it clear that he wished to remain in France.
However, he started QPR's opening Championship match today and played well, as they beat Sheffield Wednesday 2-1.
"He's got on with it today as he has all week," Redknapp told BBC Sport.
"He's been great in training and I picked him on merit, he knows the game. He tucks in little holes and passes perfectly, that's why I put him in the team."
Barton has also been linked with Everton during this transfer window.