Updated

Ryan Tannehill says he's looking forward to his second season with the Miami Dolphins, in part because they've been busy trying to upgrade his supporting cast.

This month the Dolphins signed Mike Wallace, the top pass-catcher in free agency, and wideout Brandon Gibson and tight end Dustin Keller. They also re-signed wideout Brian Hartline.

That means big changes for Tannehill, who had a solid rookie season despite an unimposing cast of wideouts who caught only three touchdown passes.

Speaking after he played in a celebrity tennis match Thursday at the Sony Open, Tannehill said he expects to show a lot of improvement in 2013. He threw for 3,294 yards last year, more than acclaimed rookie classmates Robert Griffin III or Russell Wilson.