John Carver admits Newcastle face the biggest summer in their recent history as they attempt to convince supporters they can compete once again.
The Magpies are currently treading water in the Barclays Premier League, with a chronic lack of both quality and depth in the playing staff having been cruelly exposed by suspension and injury amid a run which has seen them win just two of their last 14 games in all competitions.
That depressing sequence of results, coupled with fermenting dissatisfaction with the way the club is being run under owner Mike Ashley, has prompted calls on social media for a mass boycott of Sunday's home clash with Tottenham, and it remains to be seen how significant a response that attracts.
But whatever happens at the weekend, head coach Carver, who may or not remain in charge beyond the end of the current campaign, is convinced that the club will invest and invest significantly during the closed season to address the current deficiencies.
He said: "This is the biggest summer in the club's recent history, definitely. Definitely. We know that, everybody knows that. There are certainly a lot of decisions to be made, aren't there, especially where we are and the situation we are in?
"But that's out of my hands. I can't do anything about the protests, I can't do anything about what's going to happen next season with my position, so I have just got to stay focussed and maintain some sort of level-headedness going into these games and make sure we get the right results.
"Going back to the investment - and I said it last week and straight from the heart - they know, the football club knows that they have to invest in the team because you can only keep going for so long.
"They HAVE to invest in the team - and I have had assurances they are going to."
Carver's comments came after it was revealed that the Magpies' banked more than £34million during the last financial year in addition to reporting a profit of £18.7million.
That has done little to placate fans furious at the recent lack of investment in a squad which has been depleted by long-term injuries to Steven Taylor, Paul Dummett, Massadio Haidara, Cheick Tiote, Siem de Jong and Rolando Aarons. They have also been hit by suspensions to skipper Fabricio Coloccini, leading scorer Papiss Cisse, midfielder Moussa Sissoko and more controversially, the loss of Mapou Yanga-Mbiwa and Davide Santon, who have been allowed to leave despite a defensive crisis which is ongoing.
However, Carver remains confident a club which has more than once been able to challenge for the title inside the last two decades with Kevin Keegan and Sir Bobby Robson at the helm and twice qualify for the Champions League, can go some way towards scaling those heights once again.
He said: "We've seen it. We've got close to it under Kevin and under Sir Bob, we got within touching distance of it. We had quite a bit of investment and some good, good players, but ultimately we fell short.
"It is very, very difficult to win it [the title]. You have seen all the investment, and it does not necessarily buy success. I will use Manchester City as an example - all right, they have won it, but they ain't going to win it this year and they have spent millions.
"You have to do it the right way and invest your money in the right manner, but it does not guarantee success."
Asked if the club could ever threaten the Premier League's big boys once again, Carver added: "Threaten. We're not going to win it.
"If we invest right, why can't we go after European spots, Champions League spots? Why not? Look at Southampton - they lost so many players and had to replace them. They've done a great job this year. Every so often, a team just comes through from somewhere - like we did."