McClaren’s side are bottom of the Premier League after Saturday’s 6-1 defeat to Manchester City.
Asked if he had enough “fighters” in his squad, McClaren said: “Very well put. In the last 12 to 18 months that has been the problem at this football club.
“We’re here to turn that around and we’re going to do whatever it takes to turn that around, and you’re absolutely right – that is difficult job. That is a tough job to do.
“But we’ll do it. We’re determined to do it and get back to work on Monday.
“As you say, this is not just happening now. This has been happening for 18 months. We have to turn it around.”
Newcastle now have a fortnight to prepare for the next game, the home fixture against Norwich City on October 18.
And McClaren feels he can changing a losing mentality into a winning one.
Asked if his players have the right mentality, or are just carrying “baggage” from last season, McClaren added: “They’re going to have to start getting (the right mentality), otherwise we’re in the fight for the rest of the season.
“We’ve pointed that out over the last few weeks and to be fair the performances over the last two games have been ones of fight and quality – there’s a team in there.
“We’ve just got to have some consistency and we have to deal with setbacks a little bit better than presently.
“As you say it’s something in the history and we knew it would be hard to turn around.”