NEWCASTLE United boss Bobby Robson has stepped up his efforts to strengthen his suspect defence.

Robson has signalled his dissatisfaction with his rearguard, who have conceded 11 goals in their last five games, by making enquiries at home and abroad.

Roma defender Jonathan Zebina yesterday emerged as United's latest target after Luton manager Joe Kinnear revealed that Robson had asked about the versatile Matt Taylor.

Liverpool, Arsenal and Leeds are also interested in French international Zebina, who could be available this summer.

The 23-year-old has been linked in a part exchange deal for Liverpool's Emile Heskey. But the Premiership leaders have no intention of selling the England striker, who impressed Roma when he scored one of the goals which knocked them out of the Champions' League at Anfield last week.

The key to any move for Zebina by Newcastle lies in whether they can hang on to a top-four Premiership spot and qualify for next season's Champions' League.

But Hatters boss Kinnear is urging Robson to snap up Taylor, who is valued at £2m and out of contract this summer.

Taylor, 20, plays in defence or midfield and is also attracting interest from Sunderland and Tottenham.

Kinnear said: "Bobby was asking about him and I said he should have a look at him, quick.''

Robson has precious little cover at the heart of defence for Nikos Dabizas and Andy O'Brien, who are both fighting to be fit for Friday's home game against Everton after picking up ankle injuries in Saturday's 3-0 FA Cup quarter-final exit at Arsenal.

Aaron Hughes and on-loan Sylvain Distin, who have been operating at right and left-back respectively, could be forced to switch to the middle if Dabizas and O'Brien are ruled out.

Both men were withdrawn from international duty this week. Dabizas was due to link up with Greece for their game against Belgium in Athens and was keen to travel despite his injury.

But Robson, unhappy that Dabizas was injured when he last represented his country in a friendly, said: "Nikos told me he had to go because his coach said so. But I told him another coach did not want him to go - and that was me.''

O'Brien was injured at Highbury in an accidental clash with Shay Given.

While the United goalkeeper yesterday linked up with the Republic of Ireland squad for their game with Denmark in Dublin tomorrow, O'Brien was joining Dabizas on the treatment table.

O'Brien said: "Shay cleaned me out - we went for the same ball and he caught me on the ankle.''

After Saturday's Cup elimination, Newcastle skipper Alan Shearer insisted his side have "eight finals'' in the run-in to the end of the season.

Leeds and Chelsea are breathing down the Geordies' necks in the chase for the fourth Champions' League berth.

Newcastle are two points ahead of Leeds and three clear of Chelsea, with a game in hand on their rivals.

Shearer said: "We're all bitterly disappointed about what happened on Saturday, but we know we have eight Cup finals coming up.

"We still have a heck of a lot to play for in eight massive Premiership games.''

Meanwhile, Robson has also been linked with a £4m move for Lomana LuaLua's Republic of Congo compatriot Ariza Makukula. Newcastle coach John Carver saw the Under-21 international score the only goal for Spanish Second Division side Salamanca against Xtremadura.

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