Jarvis made his England debut against Ghana last month and Wolves are ready to rebuff a series of transfer bids for the left winger over the summer.
"Jarvis is not for sale at any price," McCarthy said. "No-one at this football club needs to be sold."
"But I read that Jarvis is meant to be going to Liverpool or wherever and it's a nonsense. He is far too valuable to us. If anyone comes knocking at my door they will get a custard pie.
"We need our best players. Why the hell should we sell him? He's one of our best players, we've just got him in the England squad, so no he's not for sale."
Jarvis, who began his career at Gillingham, signed a new five-year deal with Wolves last season.