By Tzvi Machlin The first big quarterback battle at Nebraska in the last four years is set for this summer as Casey Thompson, Logan Smothers, Heinrich Haarberg and Chubba Purdy vie for the starting job. Head coach Scott Frost weighed in on the impending quarterback battle. Speaking to the media on Monday, Frost indicated that the timetable for naming a starter hasn’t been decided yet. He said that the team is “nowhere near ready” to announce a starter yet. “The timetable is whenever it’s clear to us and to everybody,” Frost said, via Saturday Tradition. “I think there’s a lot of guys doing som…