The move was first reported by Pro Football Talk.
The Chargers placed a right of first refusal on McCain at the start of free agency last month.
The tender would have paid McCain a base salary of $1.9 million for the 2018 season. Now that the Chargers intend to rescind the tender, McCain becomes an unrestricted free agent.
McCain, 26, was productive in his first season with the Chargers last year, finishing with 20 combined tackles, five sacks and two forced fumbles in 15 games played. McCain played a total of 227 defensive snaps last season.
With McCain not on the roster and fellow edge rusher Jerry Attaochu signing with the San Francisco 49ers in free agency, the Chargers will now look to add depth to the defensive-end position in the upcoming NFL draft.