FILE - In this Sept. 28, 2019, file photo, Nebraska quarterback Adrian Martinez (2) throws a pass during the first half of an NCAA college football game against Ohio State, in Lincoln, Neb. Adrian Martinez will be a rare four-year starting quarterback at Nebraska this fall and yet, for all his experience, he's one of the team's biggest mysteries. (AP Photo/Nati Harnik, File)

FILE - In this Saturday, Nov. 2, 2019 file photo, Nebraska quarterback Adrian Martinez (2) falls to his knees after failing to pick up a first down against Purdue during the second half of an NCAA college football game in West Lafayette, Ind. Adrian Martinez will be a rare four-year starting quarterback at Nebraska this fall and yet, for all his experience, he's one of the team's biggest mysteries. (AP Photo/Michael Conroy, File)