OAKLAND — The Oakland Raiders didn’t look far to find a defensive coordinator.

The Raiders on Monday hired Stanford’s Jason Tarver, who helped shape one of the Pac-12’s top defenses while serving as co-defensive coordinator and overseeing the linebackers under rookie head coach David Shaw last season.

Tarver had spent the previous decade as a 49ers assistant, including the final six seasons (2005-2010) coaching the outside linebackers. After the 49ers hired Jim Harbaugh, Tarver went back to the college ranks to team with co-defensive coordinator Derek Mason at Stanford.

Tarver returns to the NFL with an even more monumental task.

Despite having many high-priced players on that side of the ball, the Raiders struggled mightily on defense last season. Oakland had franchise worsts in touchdown passes allowed (31), yards per carry (5.1), yards passing (4,262) and total yards (6,201) while giving up the third-most points (433) in team history.

Just last offseason, cornerback Stanford Routt, linebacker Kamerion Wimbley, defensive tackle Richard Seymour and safety Michael Huff received contracts worth more than $160 million combined. That quartet joined former top 10 pick Rolando McClain, who signed a $40 million, five-year deal when he was drafted in 2010; and defensive tackle Tommy Kelly, who just finished the fourth year of a $50.5 million, seven-year contract, on one of the league’s most expensive defenses.

And least productive.

The Raiders joined this year’s Tampa Bay team as one of the four teams to allow at least 30 TD passes and 5.0 yards per carry in a season, a distinction last reached by the 1952 Dallas Texans. The Raiders, who finished 8-8 last season, also became the sixth team since the 1970 merger to allow at least 2,000 yards rushing and 4,000 yards passing in a season.

That prompted new general manager Reggie McKenzie to fire Hue Jackson after one season as coach and hire Dennis Allen, the former Denver Broncos defensive coordinator. Allen and Tarver will share the task of fixing two long-standing problems on defense: stopping the run and reducing penalties.

The Raiders set an NFL record last season with 163 penalties for 1,358 yards.

The 37-year-old Tarver received his bachelor’s degree in chemistry from Santa Clara in 1997. He also earned his master’s degree in biochemistry and molecular biology from UCLA and the departmental prize for distinguished teaching in 1998 and 2000.

Under the tutelage of Tarver and Mason, Stanford’s defense ranked either first or second in the Pac-12 in eight categories last season. That included first in total defense (331.4 yards) and rushing defense (107.8 yards) per game in the offense-oriented league.

Stanford also lost 53-30 at home to Oregon, costing the program a shot at the Pac-12 and BCS championships. The Cardinal finished with an 11-2 record, including a 41-38 overtime loss in the Fiesta Bowl to Oklahoma State.

The Raiders now have all three coordinators in place.

Greg Knapp replaced Al Saunders on offense and Steve Hoffman is taking over for John Fassel as special teams coordinator. There are still some position coaches and lower-level assistants to fill out.