For the better part of the last decade, the Bengals' defense has benefited strongly from the presence of two particular players who are now on the open market. Those players are Reggie Nelson and Leon Hall, who were recently ranked by Pro Football Focus as two of the top 10 best available free agents remaining.
While Nelson has been much more productive over the past few years than Hall due to injury issues, Hall's talent and productivity are hard to question. He still has yet to return to the highly productive form of his first four years with the team when he recorded 71 passes defensed and 18 interceptions for 169 yards and a touchdown. But, he has done enough to remain relevant as a high-value signing.
It's been a struggle for Hall to keep up ever since a string of injury problems that began with a torn achilles tendon in 2011. He returned for a fairly productive 2012 season, but tore his other achilles tendon in 2013, causing him to miss most of that season. He played well enough in 2014 and played well enough in the slot in 2015, but was unable to retain his starting job against faster and more productive players like Adam Jones and Dre Kirkpatrick on the boundaries. Per PFF:
After a solid 2014, Hall was curiously demoted to nickel corner in favor of Dre Kirkpatrick for Cincinnati. The results weren't great for the Bengals, but Hall once again graded positively in coverage for the ninth straight season. At 31, he's a bit past his prime, but competency at cornerback is difficult to come by.
Despite the issues, Pro Football Focus ranked Hall as the sixth best remaining free agent. They note that Hall's production in 2014 outweighed his production in 2015 because of an ill-advised transition to the nickle role on defense. However, Hall produced more interceptions in 2015 (2) than 2014 (1), the same number of passes defensed (8), and only slightly fewer tackles (44 in 2015 vs 49 in 2014). Despite what PFF is saying, there didn't seem to be much of a drop off for Hall last season. Still, they note that he can continue to be a fairly productive player for an NFL team as long as he can stay healthy.
We've already discussed why the Bengals should make a play to re-sign Reggie Nelson, especially with the lack of buzz surrounding him, which could cause his market value to drop significantly. We've also know the Bengals haven't ruled his return out yet. The lack of buzz probably has to do with the fact that he'll be 33-years-old just a few weeks into the 2016 season. However, age didn't stop him from having arguably the most productive season of his career in 2015.
He put up a league leading eight interceptions for 115 yards on top of 14 passes defensed, two fumbles recovered, and 50 total tackles. He was productive as a starter for the Bengals and earned his first trip to the Pro Bowl in the 2015 season, though, an ankle injury in the Wild Card game caused him to miss the Pro Bowl. How that injury is healing could also be impacting his stock in free agency.
In response to the incredible year he had, Nelso is ranked as the fifth best free agent still available by Pro Football Focus. It's hard to say just how much longer Nelson can keep up his stellar play. But, their perspective is it's unlikely he will slow down enough to not warrant another sizable NFL contract.
The age-talent balance is always one that teams have to weigh in free agency, especially at positions that put a premium on speed. Nelson is 32 and has still graded out like a top-10 safety in coverage over the past few seasons. Just how long that will last is what teams must decide, but I don't see him dropping off a cliff within the next couple years.
At one point, it seemed like the Giants were interested in Nelson's availability. However, those rumors never materialized on top of Giants management making it clear that safety was not a high priority for them.
Regardless, it's hard to explain exactly why Nelson hasn't been signed yet. There's always the possibility that he's willing to risk not playing at all if he doesn't attract a contract he feels is worthy of his services.
Both Nelson and Hall are players who have been with the Bengals for a long time. For Nelson, he's been with the Bengals for the majority of his career, since being traded by the Jaguars for cornerback David Jones before the 2010 regular season. Hall has been with the Bengals for his entire career, since being drafted 18th overall by the team in the 2007 draft. Both have been key players at various points in their careers and would be great, veteran presences on the roster to help bring up the younger guys.
If the Bengals don't bring them back, each player would be a great pickup for any interested team.