According to Espn, the Dolphins have 16.326 million in cap room. Not too bad, for as active as the Dolphins have been in free agency the last couple of years.
http://espn.go.com/blog/miami-dolphins/post/_/id/7902/updating-miami-dolphins-salary-cap
The Dolphins are set up well financially for the long term. Miami has flexibility to work out contract extensions later this summer if it chooses. Or the Dolphins can wait to use their money next year in free agency.
http://espn.go.com/blog/miami-dolphins/post/_/id/7902/updating-miami-dolphins-salary-cap