The 28-year old midfielder joined the R's on a free transfer from the Magpies in late August and will make his bow at Loftus Road in about 40 minutes at time of writing.
"It wasn't really an issue. I had a chat with Adel and he understood straight away," Warnock told Sky Sports before the match.
"He knew exactly where I was coming from and he's seen what's come in, he's seen the type of player there is and I've said to him just to concentrate on his football.
"He's got a team now that can give him the ball in the right areas and it's up to him now, he's got the platform and he doesn't need an armband and Joey is the opposite.
"He's a captain anyhow, whether he's got an armband or not and we need that. We need leaders on the pitch and I think him and Anton (Ferdinand) talk very, very well. Luke's (Young) a good experienced player so it augurs well."
Asked if Barton would be captain for the foreseeable future, Warnock replied: "Yes, he is."