FULL-BACK Andy Griffin has put the case for the defence at Newcastle and urged Sir Bobby Robson to stick with his rearguard of rookies.

Manager Robson is on the look-out for a top-line centre-back to bolster his suspect defence.

But he has told the likes of Andy O'Brien, Aaron Hughes, Steve Caldwell and Titus Bramble to prove there is no need to splash out in the new year.

And Griffin, who has established himself at right-back after long-term injury problems, insists the fledgling Magpies can meet the challenge given time.

He said: "There has been a lot of talk about buying defenders. You can always go out and buy a centre-half for £10m and pay him £50,000-a-week, but there are still no guarantees he'll do the business.

"We are all very young in this defence - I am the oldest at 23. It's time to look at the positive side of that. We have conceded one goal in our last three League games and as far as I am concerned, we all want to go on for a long time.

"We are getting a better understanding and we believe people should look at the cost of the current back four -- £3.5m - and I cost £1.5m.

"We think we can save the club a lot of money."

Griffin is poised to make his 50th Premiership start today when sixth-placed Newcastle visit relegation-threatened Bolton.

And he warned: "There is no easy game in this league. As a top-six side we are expected to go to places like Bolton and win.

"Our away form this season has been worse than we hoped, but we have taken four points from Aston Villa and Southampton, and that's a start.

"We will respect Bolton but we need the points. Bolton do as well - they are fighting for their lives.

"At the start of the season we would have settled for the top six at Christmas.

"But if we finish fourth again this season, I'd be more than happy. Hopefully we can keep on pulling out the stops at home as well as picking up away points.''

Although he has now started 22 consecutive games, Griffin maintains: "I still don't see myself as an automatic choice like Alan Shearer or Gary Speed.

"I'm enjoying my football very much. If you compare where I am this year to last Christmas it's totally different.

"But I won't be taking anything for granted after what has happened in the past.''