Receiver isn't the only offensive position the Miami Dolphins are working feverishly to upgrade.

The Dolphins have been talking to representatives for the NFL's top-tier free-agent tight ends and have put a couple feelers out before Tuesday's signings begin.

A source told the Sun Sentinel tight end Jared Cook is high on Miami's list of possible "tier one" free-agent targets. Cook, a 6-foot-5, 246-pounder who ran the 40-yard dash in 4.49 seconds, is the type of weapon that commands the attention of defenses.

Cook, a third-round pick whom the Dolphins liked in the 2009 draft, had his breakout season in 2011, catching 49 catches for 759 yards and three touchdowns.

Cook's numbers fell off to 44 receptions for 523 yards in 2012, but he did score four touchdowns during his 485 snaps.

Cook isn't a traditional tight end considering he spent most of his tenure in Tennessee slipped out like a receiver. Blocking has also been an issue during his NFL career, but the Dolphins haven't ruled out re-signing Anthony Fasano, who is considered one of the NFL's better blockers.

Miami does have a few options at tight end, either through free agency or the 2013 draft. Giants tight end Martellus Bennett, the New York Jets' Dustin Keller, Oakland's Brandon Myers, San Francisco's Delanie Walker and Cook are the top unrestricted free-agent tight ends. Bennett is the best all-purpose tight end in the bunch. The others are pass-catching specialists.