Forwards Will Johnson (London Irish), Mike MacDonald (Leeds Carnegie) and Shawn Pittman (London Welsh) are joined by backs Junior Sifa and Tim Usasz who both play for Nottingham.
The USA take on England Saxons at Northampton's Franklin's Gardens on June 4 and Tonga at Moseley Road, Esher, four days later and then finals day at Worcester's Sixways on June 18.
The USA will aim to finish as high as possible in their pool which will determine whether they play for the cup, bowl or plate on finals days, with Canada, Italy and Russia in the other group.
The USA squad consists of 13 overseas-based players, while seven members of the squad are currently in the UK representing the United States in the HSBC Sevens World Series.
O'Sullivan said "The fact that there are some players resting gives an opportunity to others to make a case for inclusion in the final selection for Rugby Word Cup."
Forwards: Inaki Basauri (L' Aquila), Chris Biller (San Francisco Golden Gate), Todd Clever (Suntory Sungoliath), Pat Danahy (Life University), Eric Fry (Las Vegas Blackjacks), JJ Gagiano (University of Cape Town), Nic Johnson (unattached), Will Johnson (London Irish), Danny LaPrevotte (San Francisco Golden Gate), Scott LaValla (unattached), Mike MacDonald (Leeds Carnegie), Shawn Pittman (London Welsh), Louis Stanfill (Mogliano), Phil Thiel (Life University), John van der Giessen (Utah Warriors).
Backs: Paul Emerick (Life University), Tai Enosa (Belmont Shore), Troy Hall (New York Athletic Club), Colin Hawley (Olympic Club), Nese Malifa (Glendale), Mike Palefau (Utah Warriors), Mike Petri (New York Athletic Club), Mile Pulu (San Francisco Golden Gate), Junior Sifa (Nottingham), Andrew Suniula (Chicago Griffins), Roland Suniula (Boston Rugby), Kevin Swiryn (Agen), Zack Test (unattached), Tim Usasz (Nottingham).
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.