SIR Bobby Robson last night warned he will have to patch up his dodgy defence on the cheap.

The Newcastle United manager, whose back four on display at Bolton Wanderers on Boxing Day cost just £2.5m, fears his sparse transfer war chest will preclude him from spending many millions when the market opens next week.

And after seeing his hopes that he had found a settled and secure backline demolished by the 4-3 defeat at the Reebok Stadium, Robson confessed he is worried his efforts to sign a defender will ultimately be in vain.

Robson, whose side host Tottenham Hotspur tomorrow, is desperate to strengthen his defensive options when the transfer window opens for a month from New Year's Day.

But he knows his club are feeling the pinch from football's financial crisis as much as anyone and cannot bankroll a multi-million pound signing.

Indeed, he concedes that he could well have to send out a defence containing no new faces when Newcastle play their first game after the window closes, at Middlesbrough on February 1.

Robson said: "What we need is a really top-class centre-half who can give us leadership qualities and command, and they aren't easy to get. Most clubs are looking for that.

"Manchester United have a network of people looking around for players - and they still had to spend £28m on Rio Ferdinand.

"United would have liked to have been in a position to sign somebody cheaper than Ferdinand. We haven't got £28m.

"Money is tight now, and anybody who has money is trying to keep it.

"I think what we'll find is there will be no big transfers taking place; most of them will be loans.

"If that's the case, we'll be talking about more foreign players coming into the country.

"With respect, I don't think there's much in the Nationwide League that will enhance the Premiership - and you can't borrow Premiership players.

"We'll do something if we can when the window opens, but the ones we like are difficult to get.

"We're getting all sorts of players being thrown at us, but the guy coming in would have to be considerably better than what we've already got.

"I'm not decrying the players we've got. And the pressure is on them to perform to the standards I want. It's up to them."

Robson could shake up his defence tomorrow and recall Olivier Bernard after the Frenchman recovered from a knee injury.

But the manager tried to deflect the blame away from his much-maligned back four in the wake of the Reebok horror show, claiming mistakes from midfielders and a bad refereeing decision cost his side three goals.

A short-term signing is the most likely result of Robson's search, though Martin Keown's return to the Arsenal first team will prevent Newcastle from snapping up the former England centre-back.

Matthew Upson has also trained with the Magpies, but the 23-year-old may be considered too young by the Newcastle manager as he strives to bring in a more experienced head to guide his inexperienced charges.

Robson said: "I'd like Titus Bramble to be fit, but he's not. He was almost ready but then he felt the hamstring slightly.

"He definitely won't be ready for the Tottenham game, but Olivier Bernard has a chance of playing.

"We never gave Fulham a shot all game. We had a settled back four and we were good in most departments for four games.

"We did well defensively in the draw at Southampton, and we beat Aston Villa and Everton. We conceded two goals in four Premiership games.

"I'm trying to find our best back four all the time. To let in two goals in four games is terrific, and we thought we were getting it right."

Robson refused to confirm whether Shay Given will remain in the starting line-up, though the Newcastle manager absolved his goalkeeper of blame for Bolton's four goals.

Meanwhile, Alan Shearer believes referee Uriah Rennie has a vendetta against him after the Newcastle captain picked up a controversial booking at Bolton.

Rennie, the only referee to send off Shearer in professional football, enraged Robson when he cautioned the striker for dissent.

Shearer said: "I don't think we were helped by certain people and I don't think it's a coincidence; it keeps happening, and I think perhaps there is something personal there.

"I thought it was the captain's prerogative that you could go up and speak to the referee, which is what I did.

"He decided to book me for what I thought was being very polite. I thought the captain could ask the referee questions. That's what he is there for. But obviously not with him.

"If you go through the years he has refereed Newcastle, he has given me very little. I don't think I had one free-kick in 90 minutes at Bolton.

"It really amazes me but I have to be careful what I say because I will get punished. I did not swear at the referee and he will verify that."