Koa Misi signs four-year extension with Miami Dolphins

The Miami Dolphins have announced they have signed linebacker Koa Misi to a four-year contract extension.

The 26-year-old was entering the final year of his rookie deal, which would have seen him become a free agent at the end of the season.

However, the Dolphins have moved to secure the long-term future of one of their key defensive players by signing him to a deal worth $17m (£10.9m).

Miami face the Cleveland Browns in their season opener on Sunday.