Chris Armas, who suffered a Grade II sprain of the Medial Collateral Ligament (MCL) in his left knee following a tackle from behind in the first half of the Barbados match on August 16, has returned to the U.S. squad for tomorrow’s game against Costa Rica. The injury kept Armas, who had been picked by Olympic coach Clive Charles as an overage player, out of the Olympic tournament. Since his recovery, the defensive midfielder has played and started in four of the Chicago Fire’s six playoff games. Before his injury, Armas was a starter in every U.S. game but one this year before his injury and led the U.S. in minutes played.