Benjamin becomes the first member of the 49ers to sit out this season. His announcement came one day after general manager John Lynch said he had yet to have a discussion with a player who planned on opting out.
"First, I would like to thank the 49ers organization for their continued support," Benjamin wrote Tuesday night on Twitter. "After much consideration and discussion with my family I have decided to opt out of the 2020 NFL season as I feel this is the best decision for my family.
"I will continue to support my teammates and many friends around the league this season. As we continue to navigate the pandemic I wish that everyone stays safe."
Benjamin, who spent the first eight seasons of his NFL career between the Cleveland Browns and Los Angeles Chargers, signed a one-year contract with the 49ers in March. He was expected to compete for a roster spot at receiver and likely as a return man.
On Wednesday, Wilson followed in Benjamin's footsteps and became the latest notable player to opt out.
Wilson announced his decision on social media and cited the safety of his family during the pandemic.
"I've decided to opt out this 2020 season," Wilson wrote on Twitter. "It was a very tough choice but since the day I started playing the game it's always been Faith Family Football. Because of this crazy time, I choose to put my family in the best situation I see it.
"I will stand by my teammates & brothers to support them 100% throughout this season and will be counting the days until I can join them again."
Wilson becomes the second Dolphins player to opt out in as many days, joining fellow wideout Allen Hurns. More than 50 players around the league have opted out to this point.
NFL players have until 4 p.m. EDT Thursday to opt out of the upcoming season.