Update: Reggie Nelson left the Raiders' facilities today without signing a deal. We'll keep you updated as this story develops.

Reggie Nelson has left the building, so looks like nothing tonight. #Raiders — Vic Tafur (@VicTafur) April 6, 2016

Not many people expected it would take former Bengals safety Reggie Nelson this long to sign a deal in free agency, but today, he's about to exit the free agent market. According to Vic Tafur of the San Francisco Chronicle, Nelson is expected to sign with the Raiders today, pending a physical. Nelson is currently in Oakland visiting the Raiders.

Expect S Reggie Nelson to sign w/ #Raiders today pending physical. A look at his 8 INTs last year: https://t.co/yiDXVbovOt via @CincyJungle — Vic Tafur (@VicTafur) April 5, 2016

Many Bengals fans were hopeful the team would still re-sign Nelson, and Marvin Lewis admitted the door wasn't completely closed on the possibility of Nelson returning to the Queen City. But, if this report is true, the door will officially be closed.

In 2015, Nelson tallied 77 tackles, two fumble recoveries, two run stuffs, 14 pass defenses and a league-high eight interceptions. The safety returned those eight picks for a combined 115 yards, averaging 14 yards per interception return. In his six seasons with the Bengals, Nelson totaled 460 tackles, 5.5 sacks, 5 forced fumbles, 5 fumble recoveries, 17 run stuffs, 62 pass defenses, 23 interceptions and 333 interception return yards, as well as one touchdown. Nelson has been as durable as they come at safety, missing just three starts in five seasons as Cincinnati's starting free safety.

Nelson was originally selected by the Jacksonville Jaguars with the 21st overall pick in the 2007 NFL Draft, but he eventually made his way to Cincinnati by means of trade. The trade was one of the best trades in Bengals history and NFL history, as the team gave up corner David Jones, who was out of the league by 2012, to acquire a player who would become an integral part of Cincinnati's turnaround.

With George Iloka signing a five-year extension, Nelson's departure became inevitable. The Bengals need to see what they have in Shawn Williams, the team's third round selection of the 2013 NFL Draft before he hits free agency after the upcoming season. The Bengals believe Williams can offer them a lot and re-signing Nelson would have stalled his growth.

The question of whether Nelson will be able to replicate his 2015 production is legitimate, but the safety is still a valuable asset. He's a ballhawk on the back end, and he breaks up as many passes as just about any player in football. Nelson has progressed by leaps and bounds in 2014 and 2015, and while his numbers will likely go down in 2016 (simply because it's hard to see them going up) he's still an above-average safety until proven otherwise. While his age is a bit concerning, Nelson hasn't shown signs of slowing down. At the beginning of 2015 there were some questions regarding his tackling and speed, but over the course of the season, Nelson undoubetbly silenced his critics being perhaps the most effective member of the Bengals' secondary.

The departure of Nelson all but guarantees the drafting of at least one safety in the 2016 NFL Draft. While Shawn Williams, Derron Smith and Josh Shaw all look like promising prospects, the Bengals need at least one more player who can line up deep. Based on Cincinnati's draft history, the selection will probably come in the fifth, sixth or seventh round.