The move is likely to become official next month due to the cap ramifications.
Back in March, Ian Rapoport of NFL Media reported that the 49ers restructured C Richburg’s contract and in turn created $6.875 million of cap space with the expectation he would retire, so this isn’t a big surprise.
Richburg underwent hip surgery during the offseason.
Richburg, 29, is a former second-round pick of the Giants back in 2014. He played out the final year of his four-year, $4,877,346 contract with the Giants before agreeing to a five-year, $47.5 million deal with the 49ers that included $28.5 million guaranteed.
In 2019, Richburg appeared in 13 games for the 49ers, making 13 starts at center.