Raiders place safety Karl Joseph on IR, sign D.J. Swearinger and Dion Jordan

ALAMEDA, Calif. -- TheOakland Raidersplaced safetyKarl Joseph, who suffered a season-ending injury on his game-sealing interception Thursday night, on injured reserve Saturday and signed free-agent safety D.J. Swearinger. The Raiders also added defensive end Dion Jordan, the No. 3 overall pick of the 2013 draft who is serving out the final week of his NFL-mandated 10-game suspension this weekend, to help bolster their defense and fledgling playoff hopes.

Joseph, Oakland's first-round draft pick in 2016, is in the final year of his rookie contract as the Raiders did not pick up the fifth-year option last summer. He told ESPN after the Raiders' 26-24 defeat of the Los Angeles Chargers that he felt something wrong when he pushed off to jump for his interception of Philip Rivers.

Asked if it was his right knee, Joseph said yes. But reports and word out of the facility indicate that the injury is to his right foot. Oakland improved to 5-4 on the season with the win and plays host to the thus-far winless Cincinnati Bengals on Nov. 17 before playing at the currently 1-7 New York Jets on Nov. 24.

But the Raiders' secondary has been racked by injury this season. First-round draft pick Johnathan Abram, a hard-hitting safety, suffered a season-ending shoulder injury in the season opener and slot cornerback Lamarcus Joyner went down with what was described as a strained hamstring on the final series against the Chargers.

Enter Swearinger, a second-round pick of the Houston Texans in 2013 who has 14 career interceptions and has played for the Texans,Arizona Cardinals,Tampa Bay Buccaneers and Washington. Swearinger started four games for the Cardinals this season and had one pass defensed and 28 tackles with a QB hit.

At safety, he joins Erik Harris, who had two interceptions against the Chargers, including a 56-yard pick-six;Curtis Riley, who got off to a rough start and saw his reps cut down significantly after Week 3; and Dallin Leavitt, who is a core special-teams player.

The Raiders have also been transitioning cornerback Daryl Worley to safety, which would mean Oakland could have a pair of rookies starting at cornerback in Trayvon Mullen and Isaiah Johnson.

Jordan, meanwhile, addresses a big need at edge rusher with the Raiders placing second-year defensive end Arden Key, who had sacks in consecutive games before breaking his foot last week, on IR and veteran DE Josh Mauro having missed two straight games with a groin injury.

And while Jordan may not have lived up to his draft standing, his 8.5 career sacks are more than any other edge rusher on the roster save for Benson Mayowa, who has 20 career sacks, with a team-leading 7.0 this season (rookiesClelin Ferrelland Maxx Crosby have 3.5 and 2.5, respectively).

Jordan, who served a one-year suspension in 2015 for violating the league's performance-enhancing substance abuse policy for a third time, was slapped this spring with a 10-game suspension by the league for violating the PED policy by taking Adderall, a "medication Jordan has been approved to take in the past as treatment for ADHD, but for which his therapeutic use exemption [TUE] had expired," according to NFL.com.

The Raiders waived linebacker Quentin Poling to make room for Jordan, whose suspension ends Monday. Jordan can be in the Raiders' facility beginning Tuesday.