Subsequently, Geep Chryst was promoted to offensive coordinator and Eric Mangini was hired as defensive coordinator. On March 10, 2015, All-Pro linebacker Patrick Willis announced his retirement from the NFL due to repeated injuries to both feet.[7] A week later on March 17, linebacker Chris Borland, Patrick Willis' presumed replacement, announced his retirement from the NFL due to fears of the effects of head trauma.[8] These two retirements left the 49ers linebackers position group weakened as they headed into an offseason under first year head coach Jim Tomsula. Two other developments during the 49ers off season, the retirements of starters DE Justin Smith,[9] and RT Anthony Davis,[10] and the uncertainty of LB Aldon Smith's[11] availability due to his legal issues.[12][13]