The Dolphins, meanwhile, are looking for a quarterback.
The Dolphins faced an uphill battle to flip Ryan for assets, given his bloated cap figure, so getting anything in return for him is a win for Miami.
The former first-round pick of the Jacksonville Jaguars threw for 626 yards and completed over 60-percent of his passes this season. But they did get trade value out of a player they were set to release this offseason. Tennessee gets a 6th round pick in 2019 and Tannehill.
Tannehill's best season with the Dolphins might have come in 2016 when he helped the team earn a playoff spot and had career highs in completion percentage (67.1) and passer rating (93.5).
Tannehill's time in Miami was coming to a close with a new regime in place. He did not play in 2017 due to injury.
From the Titans' end the move is probably a reaction, in part, to Marcus Mariota's constant healthy issues. He went unsigned in free agency each of the last two offseasons, causing the 31-year-old to file a grievance against the National Football League and its owners for collusion, a case that was settled out of court last month. You could argue that he and Tannehill are incredibly similar - both are athletic, accurate quarterbacks and their playing style feels similar.
In order to make the trade work, the 30-year-old Tannehill has restructured his contract, reports ESPN's Adam Schefter.
The Dolphins now face a new era without a clear answer at quarterback.
He was the first quarterback taken in the top round since Dan Marino.