WELSH defender Danny Gabbidon has admitted that losing John Hartson for Wales' crucial Euro 2004 qualifier with Serbia/Montenegro would be a massive blow the for the Principality.

And the Cwmbran-raised Cardiff City star also claimed that 'Big John' is the most important member of Mark Hughes' revitalised squad.

Welsh football is on a high, largely thanks to the superb performance of Hartson, as the Dragons roar at the summit of European Championship qualifying Group Nine.

But the Celtic striker faces a race against time to recover from a back operation that could leave him sidelined for two months - and Wales' clash in Belgrade on August 20.

"John (Hartson) is a superb player and I don't feel he gets the credit he deserves," said Gabbidon.

"He works quite hard at bringing in other players in the game and from that point of view he is a huge asset.

"Nearly every other player in the squad can be replaced but John is the one man we don't have a natural replacement for.

"He's definitely the most important member of the squad and losing him would be a huge blow."

Gabbidon, too, knows all about back problems.

The Cardiff ace spent most of last season on the side lines due to a persistent back problem that baffled the medical staff at Ninian Park.

The problem was eventually put down to the fact that Gabbidon had one leg longer than the other. As a result his running style was putting added strain on his back as the body tried to compensate for the imbalance.

But a specially moulded football boot soon corrected the problem and Gabbidon ended the season as he started, in fine form.

"I know how frustrated he must be," said Gabbidon.

"Back problems are difficult to diagnose and you really have to take your time coming back from them."