McCarthy saw his side suffer their fifth defeat in eight league games since being promoted when they lost 1-0 at home to Portsmouth on Saturday.
It has left them heading into the international break only one place above the bottom three.
Wolves have picked up only one point from the three games at Molineux against the sides below them in Hull, West Ham and Pompey.
And they now face a demanding run of games against Everton, Aston Villa, Stoke, Arsenal and Chelsea when they return to action in 12 days' time.
McCarthy said: "I'm not so sure it's a reasonable start now. I wouldn't subscribe to that. It's somewhere between reasonable and whatever else people might want to call it.
"Losing to West Ham at home, drawing with Hull and losing to Portsmouth isn't good enough.
"We knew the international break was coming and it would have been great to have two weeks to reflect and enjoy a good result, but instead now we have two weeks feeling lousy before coming back on Friday week before the next game."
McCarthy expects striker Chris Iwelumo to be pushing for a place after the internationals following a lengthy injury lay-off.
He said: "I think when everyone comes back after the fortnight break he will be pushing. He will have to work during this break.
"He won't be having too much time off. He will be having to do his base fitness work that he missed to get him up to the required level."