The Miami Dolphins have signed safety Tyrell Johnson, who played his first four NFL seasons for the Minnesota Vikings.

Terms of the deal, announced Thursday, were not disclosed. The Dolphins also announced that linebacker Austin Spitler has signed an exclusive rights deal with the team.

Johnson, 26, had 28 tackles in 11 games for the Vikings last season, including three starts. He has 123 career tackles in 49 games.

The 25-year-old Spitler has played both of his NFL seasons with Miami and made 11 tackles in 16 games last season.