per Rotoworld:

Giants G/T Stacy Andrews was hospitalized Saturday night with blood clots in his lungs.
He was deactivated for Sunday's game against the Packers. Andrews, a backup for the Giants, is being treated for "pulmonary embolisms" that were thought to have originated in his legs. The Giants hope he'll be released on Monday.

this is actually a potentially LIFE THREATENING condition. Also after an episode he would be on blood thinners for a while and that's not good if you take beatings and have a risk of bleeding. I would not be surprised if they IR him. I wish him the best and hope to a fast recovery.