Dean Marlowe is a veteran of Sean McDermott's defense dating back to 2015 when McDermott was defensive coordinator with the Carolina Panthers and Marlowe was just starting his NFL career. He would follow McDermott to Buffalo and started seven games on defense over three seasons from 2018-2020 but really made an impact on special teams.
Marlowe would sign with the Detroit Lions as a free agent before the 2021 season but was released after that season and was with the Atlanta Falcons last season before the Bills traded for Marlowe right before the trade deadline. The reason was the Bills were dealing with injuries at the safety position and McDermott has confidence in Marlowe in his defense.
This offseason, the Buffalo Bills signed free agent Taylor Rapp and with Damar Hamlin recovered from his injury at the end of the regular season. They only have four spots on the 53-man roster for safeties so Marlowe doesn't fit. However, that experience in this defense is invaluable to the Bills, along with special teams play, and they should look to keep him with the franchise as a member of the practice squad.