Bykowski first joined the Vikings in December 2014. He spent all of the 2015 offseason with Minnesota but suffered an injury last August that led to his placement on injured reserve.
Bykowski returned to practice this year and worked at tackle during training camp and the preseason. He is an Eden Prairie native who helped his team win back-to-back state titles before playing offensive line at Iowa State. Bykowski was originally drafted by San Francisco in the seventh round in 2013.
Roberson played quarterback in college at Indiana and Illinois State. He joined the Vikings as an undrafted rookie free agent this spring.