Philadelphia Union have signed defender Sheanon Williams to a new contract, the club announced today. The 21-year old, originally signed on August 31, 2010 from the Harrisburg City Islanders, has emerged as one of the top right backs in Major League Soccer. Per club and League policy, terms of the deal will not be disclosed.

Williams will be available to speak to media via conference call today at 2:00 p.m. EST, following Team Manager Peter Nowak’s call at 1:30 p.m. Media can call (877) 345-5891 and enter code 2010201020 for access. Please note that this call is only for credentialed members of the media.

"Sheanon has become an important member of our club and we're very pleased to reward him with a new contract that better reflects his value," said Nowak. "He took full advantage of his opportunity with us after coming over from Harrisburg in 2010 and he continued to improve last season. Keeping Sheanon in Philadelphia is an important investment in our defense, both for the present and future."

Since taking over as Philadelphia's starting right back on September 11, 2010, Williams has started all 40 games in which he has appeared, scoring a goal and adding three assists.

Williams helped transform a defense that conceded 1.63 goals per game in 2010 into one of the league's top units in 2011, allowing only 1.06 goals per game, tied for second best in MLS. Opposing teams averaged 3.05 shots on goal per game in 2011, the best mark in MLS history, en route to 10 shutouts.

"The past 18 months has been an amazing experience and I'm very excited to remain in Philadelphia," said Williams. "I would like to thank the organization for their confidence in me and the fans for their incredible support. We made a lot of progress last season but have a lot more work to do to achieve our goals in 2012 and beyond."

Following the 2011 campaign, Williams was called up on three occasions to train with the U-23 U.S. Men's National Team in preparation for Olympic qualifying.

Prior to joining the Union, Williams played the entire 2010 season with the City Islanders in the USL second division, scoring three goals in 19 matches. He played 1,402 total minutes of league action for the Islanders in 2010 in addition to U.S. Open Cup matches. Williams was named the "Upper 90" City Islanders Rookie of the Year.

Williams played the 2009 Premier Development League season with the Carolina Dynamo, earning All-Eastern Conference honors after scoring six goals and accumulating 16 points in 12 games. He left the University of North Carolina after only one season (2008) to pursue a professional career in Europe, landing tryouts with VfL Wolfsburg (Germany) and FC Twente (Netherlands). Despite performing well on trial overseas, Williams returned to the United States in 2009.

After training with Real Salt Lake towards the end of 2009 and early 2010, Williams made his debut with the City Islanders and scored his first professional goal on April 17, 2010.

A product of the U.S. Under-17 National Team Residency Program in Bradenton, Fla., Williams has played in two youth World Cups for the United States: the U-17 World Cup in Korea (2007) and the U-20 World Cup in Egypt (2009). He was a 2007 PARADE High School All-American and earned NSCAA/adidas Youth All-American honors in 2006 and 2007.