By Doug Samuels A day after we shared Austin Armstrong was leaving Will Hall’s staff to join Nick Saban’s staff in Tuscaloosa, Southern Miss is promoting to fill the vacancy. View the original article to see embedded media. Hall plans to promote safeties coach Dan O’Brien to fill the defensive coordinator job. Ross Dellenger initially reported the promotion, and sources tell FootballScoop the same. O’Brien has worked under Nick Saban, Bill Belichick and Kirby Smart in his young career. Stay tuned to The Scoop for the latest.