The 26-year-old has been in good form this season and has netted eight goals in 33 Premier League appearances.
Republic of Ireland manager Giovanni Trapattoni has suggested Doyle would be a success at Serie A side Juventus, but McCarthy has no intention to sell.
"If a big enough club comes and asks it's difficult for anybody. That's the way of the world," he said in The People.
"Apparently Fernando Torres and Steven Gerrard might go from Liverpool, so come on - if they're targets everyone is.
"It flatters us a little bit. If Juventus came in with a massive amount of money I'd have to deal with it.
"But they haven't. I don't mind managers saying that - it's better than saying he could play for Rochdale."
Doyle is also not getting carried away with the speculation. He added: "It sounds good when you have someone like Trapattoni plugging you, but it would be big-headed saying I'd want to go.
"I'd love to go to a top club."