Through the first three days of free agency the 49ers upgraded their starting defense and brought back critical pieces of their offense.
They have opened day four by adding depth to their defensive line.
According to Ian Rapoport of NFL Network, the 49ers have agreed to terms on a one-year contract with veteran defensive tackle T.Y. McGill.
Last season, the 49ers signed McGill to the practice squad on October 20. McGill was promoted to the active roster on November 26, making his 49ers debut in a 49ers road win over the Los Angeles Rams.