Garbers has signed a contract with the Raiders as an undrafted free agent, Rachel Gossen of the teams' official site reports.
Garbers recorded 6,580 passing yards on 62 percent completion percentage over his four-year career with California, with an average of 230.1 passing yards per game in his senior season. The signal-caller also tallied 1,174 total rushing yards over 34 starts in college. Garbers is the only rookie quarterback to join the Las Vegas roster this offseason and likely will compete with veterans Nick Mullens and Jarrett Stidham for the team's third-string spot.