Chicago and San Francisco discussed a trade in October that would have sent Briggs, a Northern California native, to the 49ers. However, the Bears' grievance claims that San Francisco held contract talks with agent Drew Rosenhaus during the season, thus interfering with a player under contract.
The 49ers' counter is that they talked to the Bears first about a possible deal, then contacted Rosenhaus and the NFL Management Council about signing Briggs to a new contract. Because Briggs was designated a franchise player by Chicago last offseason and didn't reach a long-term deal before the prescribed deadline in July, he was not eligible to sign a new contract with the Bears or any other team, even if he was traded.
San Francisco dropped the idea of trading for Briggs at that point. Briggs, who got the Bears to agree not to franchise him this offseason when he signed last year's one-year tender, is scheduled to become an unrestricted free agent at the end of this month.
If the 49ers are found to have tampered, they could be fined or lose a draft pick.