SCOTLAND'S already shaky built-up to the Rugby World Cup has just got even tougher.

After a RBS 6 Nations Championship whitewash, losing Alex Dunbar on the way and then learning that Sean Maitland was "touch and go" they are now in danger of losing Matt Scott as well.

The Edinburgh centre missed the opening months of the season after having had surgery on both shoulders but had seemed to make a full recovery before he returned to club action at the end of November. When the national side came calling few months later, he slotted into the centre seamlessly after Dunbar tore knee ligaments in training before the England game.

However, Scott did take another knock to the left shoulder against Ireland. At first he hoped it would settle down on its own but further investigations showed that it needed a second operation. He has now had the surgery and he won't play again this season while his World Cup hangs in the balance.

It is still too early to be sure of an exact return-to-play timetable but in effect he has to get better inside four months to have any chance of playing in the warm-up game and proving his fitness to Vern Cotter, the Scotland head coach, before he picks the World Cup squad. His last experience of shoulder surgery kept him out for seven months, but was far more extensive.

If Dunbar and Scott were both to miss the World Cup, it would be a major headache for Cotter. Scott is the only Scottish centre to have played for Edinburgh this season, leaving the Glasgow players such as Peter Horne and Richie Vernon as the only specialist cover in Scotland while Duncan Taylor down at Saracens is the only Exile who could fill the role.

With a tough schedule of four games to go before the opening World Cup match against Japan, Cotter cannot afford any more injuries in this key position.