Buckner has also agreed to a five-year contract extension with Indianapolis that will pay him $21 million per year, according to FOX's Mike Chappell. The reported deal would make Buckner the league's second-highest-paid defensive tackle behind Aaron Donald.
Buckner, San Francisco's first-round pick in 2016, has become one of the league's top interior pass-rushers. He accumulated 19.5 sacks over the last two seasons and was named a second-team All-Pro in 2019.
The 49ers now own two first-round picks in April's draft - No. 13 overall and No. 31 overall.