Continue for updates.
49ers Hire O'Neil as New DC
Tuesday, Jan. 26
On Jan. 24, Rand Getlin of NFL Network reported O'Neil could be the "new favorite" at the time.
Mangini Fired as DC
Friday, Jan. 22
The 49ers have relieved Mangini of his duties, according to Alex Marvez of FoxSports.com.
On Jan. 18, Marvez reported that there was a "strong possibility" Mangini could return as defensive coordinator in 2016.
Tarver, Martindale Linked to 49ers Job
Friday, Jan. 22
Vrabel Reportedly Turned Down 49ers' DC Offer
Thursday, Jan. 21
Houston Texans linebackers coach Mike Vrabel rejected the 49ers' offer to become their next defensive coordinator, according to John Middlekauff of 95.7 The Game. Vrabel will remain the linebackers coach for the Texans, per Mark Berman of Fox 26 in Houston.
Dianna Marie Russini of ESPN reported Wednesday the 49ers had offered Vrabel the position.
The 40-year-old, three-time Super Bowl champion has been the Houston Texans' linebackers coach since 2014 and previously served on Ohio State's coaching staff from 2011 to 2013.
Niners Looking to Improve Mediocre 2015 Defense
After several years of dominance, the Niners ranked in the middle of the pack in terms of points allowed this past season and were among the worst in the league when it came to giving up yardage.
Losing a number of key players such as Patrick Willis, Aldon Smith, Justin Smith and Chris Borland certainly contributed to that, but there is still some talent that can be built upon on that side of the ball, with linebacker NaVorro Bowman leading the way.
O'Neil faces an uphill battle in restoring the 49ers defense.
Follow @MikeChiari on Twitter.