McCarthy believes that it will be crucial for his side get some clean sheets in order to climb out of the relegation zone.
Wolves managed to bounce back from a run of four successive defeats with a 3-2 home win over Sunderland.
He said: “Last weekend was just reward for the work we have put in. We played well, got that little bit of luck and want to build on it.
“But we need to keep a clean sheet and not concede the type of goals we have been doing.
“The win over Sunderland was the first time we have scored three times at home in the Premier League.
“But we can’t afford to concede two goals because we aren’t going to win too many matches 3-2.”
Wolves is set to face Blackburn on Saturday.
McCarthy continued: “I’ve said all along it will turn for us. We had a bad run and you have bad runs – as a player and a manager.
“We’ve had a bad spell in terms of results but not in terms of the way we have been playing.
“We had that bit of luck against Sunderland with them having a shot hitting the inside of a post and bouncing out plus us scoring a goal that was offside.”
