Nebraska's Martinez (foot) day to day

Nebraska quarterback Taylor Martinez, already slowed by a sprain to his right ankle, showed up at practice Monday wearing a walking boot on his left foot.

Offensive coordinator Shawn Watson said someone stepped on Martinez's toe in last weekend's 9-6 loss at Texas A&M. Martinez also aggravated his ankle sprain in the game, and Watson said that is the more serious issue.

Watson said Martinez watched practice Monday, but there is hope he can get back on the field Tuesday.

Watson said Martinez is day to day and that Cody Green would start against Colorado on Friday if Martinez can't play.