A spate of postponements have prevented McCarthy from featuring in recent weeks and the youngster is keen to get back into the habit of playing regular football for Terry Skiverton's side.
He told the club's official website: "I signed until the end of the month and haven't played a game yet. I'm looking to extend my loan again and get as many games as I can. I'd preferably like to stay until the end of the season and get more games but we'll have to see what Reading want.
"I said to the gaffer that I would stay until the end of the season but obviously with the situation at Reading they want it to be month-by-month in case anything happens.
"As long as Reading are happy to keep me here I'll stay as long as I can. The main thing is I've been playing week-in, week-out so I've been able to progress and work on my game."