London Fletcher and Andre Carter suffered foot injuries in Sunday's game against Seattle and their status is day to day.
Carter has a plantar fascitis sprain while Fletcher has a contusion/sprain of his foot.
Losing Fletcher would be a significant blow to the Redskins' defense as the team prepares to face the New York Giants this Sunday at FedExField.
Fletcher is the Redskins' top tackler. The Giants enter the game with the NFL's best rushing offense, led by Brandon Jacobs and Derrick Ward.
Fletcher has started 130 consecutive games in the NFL.
Complicating matters is the absence of Marcus Washington, who is unlikely to play as he recovers from a high ankle sprain.
Zorn said the Redskins have a plan in place if Fletcher is unable to go.
"H.B. Blades would be in the middle," Zorn said. "With Marcus out, then Fincher would go in. So we would have it covered. We would not have our starters, so that would be an issue for us."
Zorn even suggested that the Redskins may play more nickel defense, with an extra defensive back in the lineup.
"We'll have some guys to put in," he said. "That would be what every team would have to do if they had two linebackers out."
Carter suffered his injury in the second half of the Seahawks game. He had to be helped off the field and later went into the locker room for further evaluation.
Also, Kedric Golston suffered a bone spur in his foot, but he was able to fight through it and play most of Sunday's game.
Said Zorn of Golston: "He went to heroics. When he got down in his stance, he felt like he had good burst and that he could go. He was a real warrior."
Zorn added that he expected Anthony Montgomery, who has missed the last two games with an Achilles injury, would be available to play against the Giants.