Injuries have limited the number of appearances that the 31-year-old has been able to make over the last two seasons, but the Premier League side are eager to retain the defender's services.
"Paddy is going to get a new contract, we're quite close to agreeing something with him. I think it's another year on it. We haven't quite finalised it but that is probably what will happen," Parish told the Croydon Advertiser.
Parish also confirmed that McCarthy is likely to leave the club in the near future on a loan basis.