The current England captain, Borthwick will continue in the role at Sarries having led the side last season and he will be supported by Wikus van Heerden as vice captain.

"Steve Borthwick personifies everything on which we want to model this club - his integrity, work ethic and leadership qualities make him a perfect choice as captain," said Director of Rugby Brendan Venter. "Wikus van Heerden has the same qualities and we're lucky to have a number of players within the squad who have captained their country, club or province but we couldn't ask for two better players than Steve and Wikus to lead the side."

San Diego has hosted the event for the past four years but the organising USA Sevens LLC has signed a Letter of Intent for a multi-year commitment with Las Vegas Events to stage the tournament at the Sam Boyd Stadium in the Nevada desert city.

The 2010 USA Sevens runs on February 13-14 with the 36,800-capacity Sam Boyd Stadium the home of the University of Nevada Las Vegas gridiron team being switched from an artificial turf to a grass playing surface for the event.

"As the premier rugby event in America, we are excited to showcase this competition in Las Vegas," USA Sevens managing director Ray Peterson said. "Home to the world's most celebrated hotels and renowned entertainment destinations, the electrifying atmosphere of Las Vegas complements the dynamic Sevens experience and is a perfect fit with the tournament's international appeal."

The International Rugby Board announced that Lawrence had withdrawn for personal reasons. Marius Jonker will fill the touch judge role previously occupied by Joubert while New Zealander Vinny Munro is now the Television Match Official.

The Americas Rugby Championship will build on the success of the North America 4 tournament that it replaces, and is a key component of the IRB's Strategic Investment Programme, which includes significant investment in USA, Canada and Argentina.

The new tournament features six teams, including four provincial sides from Canada joined by the Argentina Jaguars and USA 'A'. The format unites Rugby in North and South America in a high performance sub-international structure for the first time.

"Canada, USA and Argentina are priority Unions for our High Performance investment programme and their domestic based players and coaches require a tournament format that exposes them to high level cross border competition on a more regular basis," said Mark Egan, IRB Head of Development and Performance.

"The tournament is currently structured to primarily focus on our High Performance Unions in the Region, however, it is hoped that it will expand over time to include other countries such as Uruguay, Chile, Mexico and Brazil."