The team’s acquisition of Dee Ford made Marsh expendable as Marsh played the pass-rushing LEO position last season. The 49ers also are expected to add a pass rusher in the draft.
The 49ers will save $4.7 million against the salary cap with Marsh’s release, while taking a $900,000 charge in dead money.
“Thank you to the San Francisco 49ers organization, especially John Lynch and Coach [Kyle] Shanahan for believing in me and giving me a home even if it has been short lived,” Marsh said on social media. “I loved my time in San Jose and time I spent with my teammates and coaches last season. Sad to part ways, but business is business. I promise you I will be better than I ever have been. I also want to make sure I thank the 49er faithful for embracing me and supporting me and my family. Good luck and goodbye.”
Marsh, 26, joined the 49ers off waivers from the Patriots in November 2017. He played six games that season and 16 last season.
Marsh began his career with Seattle as a fourth-round pick in 2014.