WHEN it comes to centre-backs, Newcastle have used more than their fair share this season, and come next weekend Bobby Robson will be hoping that at least two of his legion of centre-halves will be fit and raring to start the Tyne-Tees derby.

At Everton last week, Robson found himself down to the bare bones of his defensive options, and admitted if either Aaron Hughes of Steve Caldwell had been injured during the game, then skipper Alan Shearer would have been forced to revert to defence.

The problems at centre-back are one of the reasons why Newcastle have failed to keep a clean sheet since their visit to Manchester City on September 30, and they will go into the derby game having failed to prevent the opposition scoring for 24 games.

Fortunately the need has yet to arrive for their top striker to test out his capabilities at the back, and with the extra week of rest their elimination from the FA Cup has allowed, Robson is likely to have at least Alain Goma back to add to his defensive options.

But with Goma seemingly a definite departure from Newcastle, along with Spanish misfit Marcelino, Robson may be loathe to continually use players whose futures lie away from Tyneside.

The Hughes and Caldwell combination started nervously last weekend but grew in stature during their 90 minutes together at Goodison Park, and it may find itself together again at home to Boro.

However, his first-choice centre-back remains Greek international Nicos Dabizas, who has missed most of the season with a cruciate ligament injury.

Newcastle have at least half a dozen centre-halves with Premiership experience on their books, and Robson even off-loaded Steve Howey at the start of the season, believing he had an embarrassment of riches at the back.

But that has been gradually whittled away since August, and along with Dabizas, Hughes, Caldwell, Goma and Marcelino, Newcastle have also used Laurent Charvet - since sold to Manchester City - and even Warren Barton at the heart of their defence.

Robson has been forced to blood the youngsters and according to one former player who knows a thing or two about Newcastle's defence, the young guns can only be good for the future of Newcastle United.

Steve Watson saw at first hand how the youngsters coped last weekend at Everton, and like many watchers he was more than impressed.

"Like everyone else Newcastle have suffered with injuries and they've still managed to stay up near the top for most of the season," he said.

"I was delighted to see Steve (Caldwell) playing at the back, and I am a massive fan of Aaron's (Hughes)."

Watson has watched the development of the Northern Ireland international since the youngster arrived at Newcastle from Cookstown.

"The great thing about Aaron is that he's such a level-headed kid and he's so willing to learn. He listens to everything and takes it all on board.

"He's never been anything apart from really dedicated.

"This season he is reaping the rewards of that and I am delighted for him."

Hughes has become a lynchpin at the back and will de a definite starter next weekend.

Who plays alongside him is another question, but with Robson's patience wearing thin with his wantaway stars, he may decide that his home-grown talents warrant their chance to impress the boss