The San Francisco 49ers informed linebacker Elvis Dumervil on Friday that they will not pick up the option on his contract.The 49ers also tendered a one-year contract offer to exclusive rights free agent running back Raheem Mostert, and picked up the 2018 contract option of linebacker Dekoda Watson.”I want to thank Elvis for everything he contributed to our team last year both on the field and throughout our building,” 49ers general manager John Lynch said. “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, 34, played in all 16 games last season, recording 13 tackles and a team-high 6.5 sacks after signing with the 49ers on June 6, 2017.Mostert appeared in each of the 49ers’ first 11 games of the 2017 season and finished with six carries for 30 yards while adding a team-high eight special-teams tackles. He was signed to the team’s practice squad on Nov. 28, 2016.Watson saw action in 14 games and registered four tackles on defense and six tackles on special teams in 2017 after signing with the team on March 17.Mostert and his wife, Devon, along with Watson and his wife, Cristina, and their son, were named co-recipients of the 49ers’ community relations family service award.