Not only did the Eagles fail miserably in their infamous 2011 attempt to build a Super Bowl-ready secondary, but the epic backfires of Nnamdi Asomugha and Dominique Rodgers-Cromartie landed the franchise in precisely the same position almost two years later. With free agency around the corner -- the legal tampering window starts midnight Saturday -- and the draft quickly approaching, the Eagles enter the main period for roster assembly with a secondary that needs reinforcements at every position. In fact, their defensive backfield is more suspect now than it was after the 2010 season, when the club set a franchise record for most passing touchdowns allowed. Last year’s team was just the eighth in NFL history to allow at least 30 touchdown passes and intercept fewer than 10. Asomugha and Rodgers-Cromartie are headed for the exits after two woefully uneventful seasons and nobody would be stunned if the Eagles believed that both of their starting safeties from last season -- Nate Allen and Kurt Coleman -- needed to be replaced. At very least, three of the five positions (including nickelback) will have new faces going into 2013, which means the Eagles will attempt to execute the most complex overnight reconstruction project in the game. Several NFL personnel chiefs acknowledged that the secondary is the most difficult area of the defense to overhaul on the fly compared to the defensive line and linebackers. “Defensive line, I feel like typically you can find guys even as college free agents that at least have the athletic tools to play that don’t need much prep time to play,” Colts general manager Ryan Grigson said. “I mean, we played with guys on Sunday that we brought in Tuesday and threw them in at nose guard and three technique and five technique and they were at least able to get us through a game. “So, I would say the secondary you have to be a little bit more engaged, especially at the safety position.”