NEWCASTLE United boss Sir Bobby Robson could pull Kieron Dyer out of Wednesday's derby at Middlesbrough as fears grow over the England midfielder's fitness.

Dyer has been hit by a recurrence of the shin trouble that forced him to undergo double surgery two seasons ago.

The second operation involved a bone graft from his hip after it was discovered he had been playing with a stress fracture.

Robson has admitted that the 24-year-old schemer is now struggling to play two games a week.

Dyer was in discomfort after last week's Champions League victory over Bayer Leverkusen at St. James' Park, and suffered a further reaction following Saturday's 2-1 home win against Chelsea.

The rearranged game with Boro, postponed a month ago under controversial circumstances, is scheduled to be Dyer's 100th Premiership appearance for title-chasing United.

But Robson, anxious to protect him ahead of the crucial Champions League visit to Inter Milan a week tomorrow, is now faced with a dilemma.

Robson said: "Kieron is on fire - we can't stop him running - but he's had a further reaction and it's very painful.

"We don't know whether he can play two games anymore in a week. We'll have to look at it. Can he play an hour and do the damage to win us the match?''

Robson already has midfielder Jermaine Jenas sidelined with an Achilles injury.

But with Hugo Viana making an impressive return to competitive action on Saturday after three months out wit a dislocated shoulder, and Laurent Robert now free from suspension, the United manager has options.

Meanwhile, centre-back Andy O'Brien has warned £9m new boy Jonathan Woodgate he faces a fight to hold on to his place.

O'Brien partnered Middlesbrough-born Woodgate on the former Leeds defender's Newcastle debut against Chelsea.

Titus Bramble made way for the England international, but O'Brien stressed that competition for places will be fierce.

"Jonathan was under a bit of pressure, but I'm pleased for him - he's come through well,'' said O'Brien, who was recalled after being demoted to the bench for the Leverkusen game.

"Jonathan is a high-profile player, but the rest of us will make it as difficult as we can for him.

"Sometimes the players outside the team are easily forgotten, like Nikos Dabizas and Steve Caldwell, who have played their part this season.

"There's going to be a scrap for places and that's only good for the club. The fact that Jonathan is a current international and worth £9m in a transfer market that is supposed to be dead, illustrates a lot.

"He's good in the air, quick and good with either foot. I'm not going to build him up too much, though, because it's a dog-eat-dog business; I was left out against Leverkusen and I was disappointed.

"Titus had a bit of a rough ride when he first came here. I don't think his performances were bad, but people were demanding things and it takes time to settle. Jonathan needs to be given that time too.''

Chelsea defender John Terry, linked with United before they signed Woodgate, said: "You can see why Newcastle are so high in the table. They are a very good side with some exceptional players. I think Jonathan Woodgate will make a difference. He's without doubt one of the best centre-halves in the country.''

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