Read Rafa Benitez's extraordinary interview on Newcastle's transfer business

The club has signed three players – Kenedy, Ki Sung-yueng and Martin Dubravka – so far this summer.

And Benitez is looking to add up to five more players to his squad before the transfer window closes on August 9. The problem is that Benitez is having to finance much of his summer business by moving players out of St James’s Park.

Asked if he needed to sell to buy, Benitez said: “It seems it is more or less like that.

“(I have) to manage the players who have value in the market and see if we can find some players at the right price. It’s not ideal, but we’ll try to manage the best way possible. I was expecting maybe something different, but we will manage what is going on and try to be sure that we bring the best players possible with the conditions we have and try to improve the squad.”

Owner Mike Ashley pledged to back Benitez – whose contract runs out next summer – with “every penny generated by the club” at the end of last season.

The club, which finished 10th last season, banked more than £123million from the Premier League last season, yet Benitez is struggling to finance deals.

Asked if he found it strange that there was no money, Benitez said: “I don’t do the numbers.”

Can Benitez improve his squad with a shoestring budget?

“I hope so,” said Benitez. “I have been trying hard for two months to be sure we have players to bring in on loan.

“If you don’t act quickly, then you lose the opportunity, and the next player is more difficult and the next maybe doesn’t have the same quality.

“There’s another message for our fans. If anyone wants to criticise anyone of our players, they have to realise it’s not that you are signing the first on your list or the the second of the third.

“Sometimes you have to wait and sign the player that’s available and make sure this player is giving everything.

“This is the positive thing about our squad. They were giving everything and that is why we were promoted and finished tenth. So massive credit to our players.”

Ashley wants Benitez to sign a contract extension.

Benitez, however, will wait before discussing his future. The 58-year-old could reluctantly walk away from the club next summer.

“We were talking about the situation at this time,” said Benitez, speaking from the club’s training camp in Ireland. “After, we were talking about numbers and the possibility of an extension.

“But I don’t think an extension is an excuse for anything. If you sign a one year extension, what does that mean for the players who have a five-year contract? It’s nothing. It’s not an issue.

“A lot of clubs have managers, they finish a contract, but still they improve the squad to be sure they are better.

“I don’t think it’s an issue with my contract. I told Mike and (managing director) Lee Charnley and Justin (Barnes, an Ashley associate).

“They know that if we do the right things then I’m keen to stay here for five years or whatever. There is a way to do things, and we have to be sure that we do that. If you want to sign an extension for a lot of years, the main thing has to be the Academy, for example. You have everything in place.

“I’m really pleased with the fans, the city, the atmosphere at the games, the staff are professionals, everyone. We have all the potential to grow and to be a top side, a proper top side.”

Asked when he would look at his contractual situation, Benitez said: “The last conversation was ‘oh, we can talk’. But I think it’s more important to be sure that we do the right things now, and then after we have plenty of time to talk about that.”

“Again, I would say my contract’s not an issue. I’m doing my best and a lot of managers, they finish a contract and still the clubs are investing and trying to improve the squad.”

Benitez believes that Newcastle’s fan base “understand the situation” he finds himself in at the club.

“I read your newspapers, and I know that the fans are clever,” said Benitez. “Our fans, they understand the situation.

“Everybody is expecting that if we can compete, be stronger, then Rafa will be pleased and then everything is happy here.

“I don’t think that the fans don’t know the situation. I’ll try to do my best, and then, hopefully in a few weeks, things can be better and then we can keep talking.”