The 49ers also hired former Dolphins RBs coach Jeff Nixon to coach tight ends. These moves fill the major pieces of the 49ers coaching staff.
O'Neil was hired by the Browns in January of 2014 and then let go earlier this month. His NFL coaching experience includes stops with the New York Jets and Buffalo Bills.
Other candidates for the job included 49ers linebackers coach Jason Tarver, who will remain as the team's outside linebackers coach, and Baltimore Ravens linebackers coach Don Martindale. Texans linebackers coach Mike Vrabel had been offered the job, but turned down the 49ers to remain in Houston. Even Mangini was considered a strong candidate prior to his firing.
Update: As expected, Jason Tarver will remain with the #49ers as the OLB coach.
— 49erswebzone (@49erswebzone) January 27, 2016
From the official Cleveland Browns website:
In his first season as defensive coordinator, O'Neil's unit made significant increases in nearly every major defensive statistic, including red zone defense (29th in 2013 to fifth in 2014), third down defense (31st to 11th), points per game (23rd to ninth) and quarterback rating (16th to first). The team led the NFL in opponent completion percentage (57.1), opponent passer rating (74.1) and passes defensed (99). The Browns finished second in the league with 21 interceptions, the team's highest total since 2008, while also finishing tied for fourth in takeaways (29). Cleveland's defense also finished in the top-10 in the league in pass defense (fifth with 6.44 yards per attempt) and total defense (ninth with an average of 5.24 yards per play).
| Browns Defensive Stats per Game (Rank) | ||||
| Year | Scoring | Total Yards | Passing | Rushing |
| 2014 | 21.1 (9th) | 366.1 (23rd) | 366.1 (23rd) | 141.6 (32nd) |
| 2015 | 27.0 (29th) | 379.2 (27th) | 250.8 (22nd) | 128.4 (30th) |