Scotland full-back Hugo Southwell was ruled out of September's Rugby World Cup on Wednesday after struggling to recover from a knee injury, the Scottish Rugby Union (SRU) confirmed. The 31-year-old had been battling to prove his fitness ahead of the tournament and was hopeful he would be able to return to action before Scotland's opening match with Romania on September 10. However, Scotland manager Andy Robinson said an early decision had been taken to exclude Southwell from contention as the former Stade Francais player would be unfit to take part in the squad's pre-World Cup training camp. "After talking this through with Hugo, we've taken the decision to stand him down from our Rugby World Cup squad by mutual consent," Robinson said in a statement on the SRU website. "Hugo has been working hard to recover from a knee injury but has not been able to take a full part in our training camp and while he may be fit to resume playing in mid-to-late August, both Hugo and I have decided that he will not be part of our World Cup plans. "Hugo has been very diligent in his rehabilitation programme and I'm sure he will be determined to perform for Scotland again in the future." Southwell played five games in the 2007 tournament in France. He will not be replaced, leaving Robinson with a 38-man preliminary squad. Scotland will name their final 30 for New Zealand on August 22.