UCF quarterback Darriel Mack Jr. suffered a broken ankle in non-football related activity this week and will miss fall camp, coach Josh Heupel said Wednesday.”We hope Darriel has a speedy recovery, but we are excited about the talent we have in the quarterback room to start the season,” Heupel said in a statement.Mack battled with Notre Dame graduate transfer Brandon Wimbush and others through spring practice, with the competition expected to continue in camp. There was no announced timetable for Mack’s return.He stepped in late last season when starter McKenzie Milton went down with a gruesome injury to his right leg that required several surgeries and nearly resulted in amputation. Milton is expected to sit out all of the 2019 season.Mack, a sophomore, completed 51 of 100 passes for 619 yards, with three touchdowns and one interception. He also ran 69 times for 337 yards and six scores. Mack led the team to a 2-1 record in his three starts, with a 40-32 loss to LSU in the Fiesta Bowl snapping the Knights’ 25-game winning streak.