In a seemingly sudden and stunning development, free-agent quarterback Alex Smith is in negotiations with the Miami Dolphins, according to an NFL source.

Smith led the San Francisco 49ers to the NFC championship game last season and although he was a free agent, the assumption through most of the offseason what that he would return.

The 49ers leap into the Peyton Manning derby, though, changed the dynamics of the NFL universe. Smith visited today with the Dolphins, who earlier this week made a pitch for Manning and another free-agent Matt Flynn.

Manning informed the Dolphins he would not be playing there and Flynn agreed Sunday to a deal with the Seattle Seahawks.

The Dolphins then turned to Smith, who will get a multiyear deal worth about $8 million a year.

So where does that leave the 49ers? If they don’t get Manning, who has not operated the West Coast offense coached by Jim Harbaugh, would the 49ers bring in Matt Hasselbeck, who is currently the starting quarterback for the Tennessee Titans, who are also in on Manning, along with the Broncos?

Follow? This could be one of the most bizarre episodes of quarterback musical chairs in NFL history.