The Black Cats now prop up the Premier League table after defeat at home to Crystal Palace.
Moyes said: “We are probably paying the price for not recruiting earlier.
“What would you say about last year or the year before that, would you say you are paying the price for recruitment then?
“Ultimately, you have to get good players on the pitch and we are not getting enough good players on the pitch."
He added: “We're going to have to improve on what we've got to give ourselves a chance."