Rafael Benitez has questioned whether Newcastle are ready for the demands of the Premier League after a dispiriting start to the season.
The Magpies won the Championship last season under Benitez, to return to the top flight at the first attempt, but they have failed to score or pick up a point in their opening two fixtures this season.
Newcastle have been quiet in the transfer market since earning promotion and, after Sunday's 1-0 loss at fellow promoted side Huddersfield, Benitez warned that it might take a while for his team to get up to speed.
"My experience in the Premier League is that you have to take your chances because, if you make mistakes you will pay for that," said Benitez.
"It's maybe because it's a learning process so we have to learn quickly, maybe it's too soon for us."
Asked if that learning process would take longer than people expect, he replied: "Yes, for sure."
The Magpies scored 85 league goals last term, 29 more than Huddersfield, but rarely tested Jonas Lossl on Sunday, even after introducing Joselu for a debut from the bench.
Sunday's newspapers carried suggestions West Ham's Andy Carroll could be a target to return to his boyhood club on loan, though Benitez was unable to confirm whether anything was imminent.
"There's no news," he said. "I haven't read the newspapers, we have to wait.
"Obviously we are working behind the scenes trying to do things but I don't know which is our position at the moment."
And Benitez remains optimistic that his side already have enough quality to avoid an immediate return to the Championship.
Asked if his side are good enough to beat the drop, he said: "Hopefully, yes. Because I am sure we will improve.
"We will need time, but I am sure we can improve. Does the team have goals in it? Yes, I think so. I think we will improve, and we will create more chances and score goals, for sure."