If Christian Kirksey is not an option, and the Buffalo Bills want a more experienced player than Howard, there are a number of free agents that could fit the role. One of those players is Rashaan Evans, who was a first round pick by the Tennessee Titans in the 2018 NFL Draft.
He played four seasons for the Titans and had 50 career starts during that stretch. Evans would have 95 or more tackles in two of those seasons and did a pretty good job in pass coverage by allowing only two receiving touchdowns during that period.
This past season, Evans played with the Atlanta Falcons and was a key part of their defense. He started all 17 games and had 159 total tackles with four passes defended and two sacks.
Recently, Rashaan Evans was signed to the practice squad of the Philadelphia Eagles but his time only lasted four days before he was released. It certainly was surprising but it could be a situation similar to Kirksey where Evans didn't think he had a chance to make an impact and is looking for a starting job.