The 22-year-old has been out on loan six times during his five-year spell at the Madejski Stadium, but with Adam Federici now seemingly out of favour, McCarthy wants to establish himself in the Royals first team.
"I hope I can get a run in the Reading team now," McCarthy said.
"I played in the Championship last year and I've been wanting to play in the Premier League for a long time. It's a massive league.
"The game's a lot quicker so I was pleased to get a start and I hope I can go on and build from that.
"I just have to get on and play my best. Obviously I want to play for England one day and this can give me a good chance to do that."