Scotland star and Alloa local Grant Gilchrist has been ruled out of the rest of the Rugby World Cup after suffering a groin injury in Sunday's victory over the USA in Leeds.

The lock forward was forced off in the 19th minute of the match at Elland Road and it was later confirmed that the Edinburgh man would not play any further part in the tournament.

Gilchrist, who had battled back from a serious arm injury to make head coach Vern Cotter's final squad, took to Twitter to express his disappointment at the news.

He said: “Devastated. Big thanks for the support. All the best to the boys for the rest of the tournament #AsOne #RWC2015”

The 25-year-old had featured in both of Scotland's matches having also started in last week's 45-10 win over Japan.

London Irish forward Blair Cowan has been called into the squad as a replacement ahead of Saturday's match against South Africa in Newcastle.

Cotter said: “We’re all really disappointed for Grant who is an important player to the group, both as an athlete and a decent human being.

“Blair, who comes in, was a bit unfortunate to miss out on selection in the initial 31-man group, but has shown great character to continue his work, stay fit and focused, in case such an opportunity came up.”

Scotland play the Springboks on Saturday before concluding the group stage when they face Samoa.