Newcastle managing director Lee Charnley described Premier League relegation as "both unacceptable and totally unexpected" after club accounts showed a £70 million outlay on players in a bid to stay in the top flight.
The full financial impact of relegation will become apparent in the next set of accounts, Charnley said, even though Rafael Benitez appears on course to lead the Magpies back into the Premier League from the Championship at the first attempt.
Newcastle on Thursday reported their accounts until June 30, 2016, showing the club recorded a profit for a sixth successive year, but the figure of £4.