That's because Hendricks is considered the top backup linebacker at all three spots, not just in the middle behind Zach Thomas.
"I have to be ready to get in there and step in," Hendricks said Monday. "I'm not going to be in there by myself. It's not like I'm going to be out there on an island."
The injury is disappointing because Seau has been coming on steadily in the Dolphins defense, and he was borderline dominant against the Giants, with a team-high 16 tackles.
"Junior is getting better every week and he's getting more comfortable in the defense, and that's good," Wannstedt said.
In other injury news, Wannstedt said center Tim Ruddy is hoping to be able to practice Wednesday. Wannstedt said a decision on who would start at center wouldn't be made until it became clear Ruddy was ready go to.
As for defensive tackle Tim Bowens, he will wearing padding on a lacerated hand but should be ready to play Sunday at Jacksonville.