Tolzien is practice squad eligible.
He has been on the game day roster for only 3 games in his career. You are eligible until the 10th game active.
This season with the expansion of 2 spots on the practice squad those 2 are allowed to be over the 3 year limit. There are new rules this year and you may want to read about it.
http://espn.go.com/blog/tennessee-ti...ad-eligibility