The 2013 Delaware Investments U.S. Open will be without its 2011 champion and world No. 8, Amr Shabana, who has been forced to withdraw from the tournament. World No. 14 Sarah-Jane Perry has also been forced to withdraw due to injury.
Shabana's absence has moved Spaniard Borja Golan into the seventh seed main draw position where he will now face Canadian champion Shawn Delierre, who has moved into the main draw from qualifying because of the Egyptian's withdrawal.
Fellow Egyptian Tarek Momen now slots in as the eight seed and will face a qualifier in the first round of the main draw.
The women's draw also sees movement with the withdrawal of Perry.
Perry told her followers on Twitter: "Thanks for all the concerned messages. I'm gutted I've had to pull out of the Carol Weymuller Open, U.S. Open, and Monte Carlo. Was really looking forward to playing but, unfortunately, injury has forced my hand. I'm determined to come back stronger, fitter and hungrier!"
Perry's withdrawal has moved American world No. 23 Amanda Sobhy into the 16 seed position, changing her first round match as a result.
Previously set to face world No. 2 Laura Massaro in the first round, Sobhy will now take on Guyana's world No. 19 Nicolette Fernandes. Fernandes beat Sobhy in the last round of qualifying in four tight games at the Carol Weymuller Open in Brooklyn on Wednesday . English world No. 35 Victoria Lust will slot into Sobhy's previous position from the qualifying pool to face Massaro.
Lauren Briggs has also withdrawn from the tournament, and has since been replaced in the main draw by Canadian world No. 32 Samantha Cornett.