The Niners announced Friday that they will not be picking up the option on Dumervil's contract for 2018. That means Dumervil will be free to sign with another team next week, though general manager John Lynch didn't completely rule out a reunion at some point.
"I want to thank Elvis for everything he contributed to our team last year both on the field and throughout our building," Lynch said in a statement. "Not only did he bring a great deal of veteran leadership to our locker room at a time of significant change, but he provided a spark to our defense. Although Elvis isn't in our current plans, we would never close the door on a potential return in the future. As a long-time friend, I wish him and his family well."
Dumervil, 33, was due to receive a $500,000 roster bonus on Tuesday if he was still with the Niners at that time. Had the 49ers exercised the option to keep Dumervil, he was scheduled to count $4.25 million against the cap in 2018.
After signing with the Niners in June, Dumervil led the team in sacks with 6.5. While appearing in all 16 games, he was mostly limited to playing in obvious passing situations, averaging just under 20 snaps per contest.
Along the way, Dumervil became the 32nd player to reach the 100-sack milestone since sacks became an official statistic in 1982 and the first player under 6-foot-1 to do so. He also joined John Abraham as the only players to record at least a half-sack against all 32 NFL teams.
But the 49ers are poised to go in a different direction at their "Leo" defensive end spot. They re-signed Cassius Marsh earlier this offseason and still have other options -- including Arik Armstead and Pita Taumoepenu -- they're hoping can develop in that spot. At the NFL scouting combine, Lynch said Eli Harold also would get a look at the position.
Even with those players in place, edge rusher remains a pressing need for the 49ers. They finished tied for 26th in the NFL in sacks (30) in 2017 and have not had a player post more than 8.5 sacks in a season since 2012.
Considering the lack of difference-making edge rushers on the free-agent market, that need might not be addressed until the NFL draft (the 49ers hold the No. 9 overall pick).
In other roster moves made Friday, the Niners announced that they did exercise the 2018 option to retain linebacker Dekoda Watson and offered running back Raheem Mostert the one-year tender for an exclusive-rights free agent. Both are considered core special-teams contributors.