Martinez's father, Casey Martinez, wrote in an email to The Associated Press on Monday night that the senior quarterback has a "debilitating injury" near the ball of his left foot that could take until February or March to heal fully.
"Taylor's injury happened in week one and after several months of rehab we have discovered that the more he does on it the worse that it gets," Casey Martinez wrote. "Very, very unfortunate location and aggravating injury that can't be toughed out.
"This is a nightmare way to finish your college career, by getting this kind of injury in the first week of the season, which essentially has cost Taylor his whole senior season as well as many team and personal goals."
Casey Martinez wrote that he has spoken to a foot specialist who works with elite athletes but did not recall the medical term for his son's injury. Pelini originally called the injury a turf toe, but has described it as a sprain the past two weeks.
Taylor Martinez has not spoken to reporters since the Oct. 26 loss at Minnesota.
Asked about the possibility of Martinez playing again this season, Pelini said, "I don't know if the chances are real good."
Martinez has been limited to four games because of injuries to his shoulder, hip, abdomen and foot. Pelini said the injuries to the second and third toes on his left foot have not "gotten much better."
Martinez has been the starter since his freshman year. The senior holds career school records for total offense, passing yards and touchdown passes. Tommy Armstrong Jr. has started five games in Martinez's place.
Nebraska (7-2, 4-1) hosts Michigan State (8-1, 5-0) in a key Big Ten game Saturday.
The Associated Press contributed to this report.