WASHINGTON -- D.C. United have returned home to RFK Stadium for a brief interlude between trips to warm-weather preseason locales, giving veterans and staff a chance to reconnect with family while newcomers like Danny Allsopp -- the Australian striker who was officially introduced in a Tuesday morning press conference -- scramble to find housing and get acquainted with the Washington, D.C. area.Compared to the focus and isolation of offsite training camps, the squad's schedule is crowded this week as logistical duties like team photos, video shoots and media sessions are taking place in addition to daily practice activities.On the field, Curt Onalfo's charges continue to improve their fitness levels and bond as a team, welcoming several familiar faces back into the fold as Troy Perkins and Chris Pontius returned from their stint with the U.S. national team while Santino Quaranta and Julius James rejoined full-contact activities for the first time since foot and shoulder surgeries, respectively."We've put a lot of quality work in to get the guys fit, played some good games down in Florida, some good competition, and saw signs of things coming together," said general manager Dave Kasper. "Pontius, Troy, they haven't really been with the team, so it's good that we can rate them. Tino is back, cleared, same for Julius James. It's good to get everyone back so we can start this next phase of preseason."But those signs of progress have been tempered by injury setbacks for two key veterans.Clyde Simms and Marc Burch, who collectively started 53 games and played more than 4500 minutes in league play for United lastyear, have been diagnosed with knee and foot injuries that seem likely to jeopardize their involvement in First Kick 2010 at the end of the month.Simms has torn his meniscus and was set to undergo arthroscopic surgery on Tuesday afternoon. The influential holding midfielder could be sidelined for as long as a month and will be forced to play catch-up when he returns to action in the opening weeks of the season. His absence represents a blow to the D.C. defensive corps that has been a central focus of Onalfo and his staff thus far, though the news about Burch could turn out to be even worse.The defender has a stress fracture in his foot, a condition that might or might not require surgery but likely means two months of recovery -- a major stumbling block for a player expected to make significant contributions at left back and center back, as well as left-footed set piece duties.After Tuesday's training session at RFK, Quaranta described his chagrin at finding himself sitting next to Burch in the doctor's office this week, receiving permission to resume regular training just as his teammate began the long road back from a debilitating foot injury of his own."It's rough, man," he said. "I got cleared, and [Burch] was taking the reins over up there."We have a good group of players here. It's been unfortunate, some of the injuries that have happened in the first part of the season," added Quaranta, "but we'll deal with it. Some of the other guys will step in."Charles Boehm is a contributor to MLSnet.com.