Mora's fourth season in 2015 saw the arrival of freshman quarterback Josh Rosen, a rash of injuries, and erratic play by the offense. The Bruins finished 8–5, including a loss to Nebraska in the Foster Farms Bowl. The Bruins finished 4–8 in 2016. In the 2017 season opener, Rosen completed 35 of 59 passes for 491 yards and four touchdowns to rally UCLA to a 45–44 win over Texas A&M. The Bruins overcame a 34-point deficit, the largest comeback in school history and the second-most ever in the Football Bowl Subdivision (FBS). On November 19, 2017, UCLA announced the firing of Mora following 23–28 loss to USC at the Coliseum.