NEWCASTLE boss Bobby Robson yesterday acted decisively to fill the yawning void left by the loss of injured Kieron Dyer when he beat off competition from Leeds to complete a £5m swoop for Nottingham Forest's midfield prodigy Jermaine Jenas.

On a day of frantic transfer activity at St James' Park, former England defender Warren Barton ended six-and-a-half years at Newcastle with a move to Derby County for a nominal fee.

But the big talking points were the arrival of teenager Jenas, and the rigorous fitness tests requested last week by England coach Sven-Goran Eriksson which may have resulted in World Cup hopeful Dyer being sidelined for up to eight weeks with a stress fracture of the left foot.

The 22-year-old schemer, who only returned to first-team action in December after nearly ten months out with a stress fracture of the shin in the same leg, underwent a treadmill work-out at Eriksson's behest last Wednesday but felt pain in his foot the next morning.

Former England manager Robson, who remains optimistic that £20m-rated Dyer will be playing again next month, explained: "Kieron did a specific test for the FA last Wednesday, when he had to test his stamina, endurance and speedwork.

"It was the England manager's decision that he needs a record of the fitness level of every player going to the World Cup.

"The request from the FA was made some weeks ago and we said we'd do it when it was right for Kieron. He'd been in the starting line-up for five weeks and he was in pretty good condition.

"He did some mileage on a treadmill, had a great test and produced a good report.

"But the next day in training he felt this problem. We had his foot x-rayed and we gave him a fitness test before the Peterborough game on Sunday, but I took one look at the pitch and decided I wasn't going to play him anyway.

"We sent him for further scans on Monday because his foot was as painful as it had been on the Thursday, and they detected the crack.

"He doesn't recall being stood on or whacked. Whether it's down to the treadmill test or not, I don't know. It's a completely different injury to the last one, but the same leg. I think it's just rotten luck and Kieron is a bit distraught about it. I have let him go home to Ipswich for a few days.

"It's more or less confirmed that he has a foot stress fracture and it's six to eight weeks out. The good thing is that it was diagnosed early. Had he played at Peterborough, it would have got worse and it would have been a bigger crack.

"He can swim and cycle and do weights, and when he can put his foot on the ground to run, he'll train and step it up. There's a good chance he'll be playing in the middle of March.''

Robson recalled that during his time in charge of the national team, similar fitness tests were carried out on players before the 1986 World Cup in Mexico, but only because of the need to assess their reactions to altitude.

"For '86, we needed to know fitness levels before we went to Mexico,'' said Robson. "Once we were there and they acclimatised, we tested them again.

"But that was a different scenario - they're not playing at altitude in Japan and Korea. You'll have to ask the FA why they needed this special test this time.''

The Dyer blow prompted Robson to implore chairman Freddy Shepherd to loosen the purse strings and release urgent funds for a replacement in the shape of England Under-19 skipper Jenas.

It also underlines Robson's determination to compete with the Premiership elite for the country's best emerging players.

"Jermaine is a young talent, but we're not paying buttons,'' said Robson. "The board have responded to the situation, which delights me. It's a short-term buy as well as a long-term buy.''

Jenas last night agreed personal terms and he will complete his move if he passes a medical on Monday morning.

Cash-strapped Forest boss Paul Hart has tipped Jenas to blossom into a ''top-class player'' after reluctantly agreeing the deal.

He said: "It was inevitable we were going to lose JJ when a suitable offer came in and the fact is £5m is a lot of money for an 18-year-old. Having said that, I have no doubts Jermaine can go on to make further progress and develop into a top-class player. He is level-headed, naturally gifted and you can only see his career going one way.''

Jenas will be 19 two weeks on Monday, the same day Robson celebrates his 69th birthday.

Aware of the 50-year age gap, Robson joked: "We'll have a joint party - and he can pay!''

Gary Speed is a surprise inclusion in the squad for today's home game against Bolton after making a rapid recovery from a broken toe.

Robson revealed: "Gary has trained with his boots on and didn't suffer any pain, so it's a possibility he'll play. He's only been out two of the recommended three weeks, but that says everything about his character.''

Fellow midfielder Robert Lee is also back in training after a calf injury and should be in contention for the home game with Southampton a week today.

Meanwhile, Robson paid tribute to 32-year-old Barton, who Kevin Keegan signed from Wimbledon in June 1995 in a £5m deal.

Barton becomes new Derby boss John Gregory's first signing.

"We thank Warren for his marvellous service,'' said Robson. "He's behaved impeccably on the pitch, in the dressing room and in the community - he's been a jewel.

"It was left to him to decide, but I'm never happy about losing players like Warren.

"He's still a Premiership-class player. There's a fee involved, but the chairman has been more than reasonable with Derby, because Warren was on a Bosman free at the end of the season.''

Barton said: ''It was a very easy decision to join Derby. This is a big club with a big manager and John Gregory was also a major part of me making the decision.

''I played the first 15 games of the season for Newcastle, got a slight injury and they went on an incredible unbeaten run. 'That made life frustrating, but I have kept myself fit and I wish the chairman, manager and fans of Newcastle the success they deserve. I have no doubt that they will continue to challenge for top honours right to the end of the season.'

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