GRAEME Souness revealed that Newcastle United have employed a new doctor to investigate the cause of the club's perpetual hamstring problems - Kieron Dyer's in particular.

The United boss reckons his players have lost over 300 days of football to hamstring injuries over the last two years - twice as many as normal in the Premiership.

Souness believes about 90 days a year is standard, but hamstring injuries are on the increase generally and the finger of blame by many - including the Newcastle boss - is pointed at the new Premiership playing surfaces.

Premiership and Football League chairmen are trying to avoid re-laying traditional turf at their stadiums, because of the lack of endurance and expense of replacing it halfway through a season.

Instead they are installing a new endurable synthetic playing surface, which binds fibre and grass together.

Consequently, players - especially those who wear boots with blades rather than studs - can't get the same sort of grip on the surface.

Players are prone to sliding rather than stopping and this is causing greater stress on the hamstring muscle.

Souness believes the Magpies' problem has increased threefold in comparison to others because they also train on the synthetic surface at their Little Benton base during the week.

He also revealed that former Blackburn boss Brian Kidd had hamstring problems with his players until he ripped up their training ground surface prior to Souness joining the Ewood Park outfit.

The 52-year-old Scot believed he had finally reduced the risk three weeks ago when they moved to a traditional playing surface.

But with Dyer suffering yet another setback, and Titus Bramble going down with a similar problem prior to United's game against Portsmouth on Saturday, the club have called in an expert in a bid to solve the problem.

"We've employed a new club doctor, Guy Stevenson, and it is now over to him to investigate," said the United boss.

"He is a specialised orthopaedic doctor and he's been working in Newcastle. I haven't sacked anyone but we felt we needed someone else in.

"It's not career-threatening but it is a concern. I want to get him on the pitch because he is one of our door openers.

"A little bit of magic from him would have got us a goal at Portsmouth, as could Nobby Solano, Emre or Alberto Luque.

"Dyer has a problem with both of his hamstrings and I wouldn't want to speculate any further."

Dyer's Newcastle career has been punctuated by long absences through injury and his teammates take great pleasure in ribbing him when the pins in his leg set the alarm off when they go through customs while travelling abroad.

But the 26-year-old England international, who signed a new four-year contract during the summer believed to be worth £90,000 a week, has missed the last 18 months largely because of a hamstring.

The injury sustained in the 0-0 draw at Aston Villa two seasons ago caused him to miss United's push for a Champions League place and the UEFA Cup semi-final against Marseilles.

Dyer then missed four months of play last season in two separate spells. Had he avoided injury during Newcastle's UEFA Cup quarter-final second leg tie against Sporting Lisbon the club would probably have advanced to the semi-final and maybe further. His pace and skill tormented Lisbon throughout until he had to limp off.

Dyer suffered discomfort after only 75 minutes of this season's curtain-raiser at Arsenal andbroke down completely 15 minutes into the clash against Manchester United at St James' Park.

The club thought they had finally rectified the problem and he was due to travel with the squad on Friday evening, only for the injury to raise its ugly head once more.

"He'll be very frustrated with the situation," added Souness. "He loves playing football because he does it so well. It will be hurting him."

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