Even before he worked out for the Denver Broncos on Friday, Peyton Manning threw passes for the San Francisco 49ers and underwent a physical exam earlier this week, according to league sources. The Arizona Cardinals have been informed they would be wise to proceed without Manning as a candidate to join the team, and will retain quarterback Kevin Kolb, paying him a $7 million roster bonus due after a Friday deadline of 4 p.m. ET.

That leaves three teams as finalists to sign Manning, including the Tennessee Titans.

Talks with the Miami Dolphins were described as “positive,” but he informed them midweek they were not going to be among his finalists, sources said.

Now San Francisco is the sleeper team few were expecting.

Manning worked out for the 49ers on Tuesday night at Duke in Durham, N.C., with coach Jim Harbaugh and offensive coordinator Greg Roman witnessing a passing session that was described by a source as “very impressive” — enough so that the 49ers sent a doctor to Durham to conduct a physical exam Wednesday.

Once Manning works out for the Titans, the process of football discussions, medical reviews related to his neck surgeries, physical workouts and parameters of a contract will be in place for the quarterback to make a decision on his next team.

There is no known deadline for Manning’s decision, but the process has been exhaustive since he was released March 7 by the Colts. Before Friday’s visit with Denver, it was Manning who insisted upon working out for the teams, endorsing the integrity of the process.

Manning first visited the Broncos March 9, followed by a visit to the Cardinals, but there were other unreported developments last weekend, such as the Seattle Seahawks parking a jet at an airport in the Denver area in a failed attempt to visit with the quarterback, according to sources.

Manning returned to Indianapolis after his Arizona trip to get an updated MRI on his neck. It was in Indianapolis where he visited with Dolphins coach Joe Philbin and offensive coordinator Mike Sherman. Sources also say Manning had a meeting with Dolphins owner Stephen Ross in Durham, where he has spent time working out at Duke.

The majority of teams that were provided with the latest medical data, including their own physical exams and extensive quality video of Manning’s throwing sessions at Duke, had informed the quarterback that it was not necessary for him to physically work out for them.

While contract parameters have been discussed, extensive negotiations involving contract language also must be completed. Sources say that Manning will provide any team that signs him with appropriate financial protection in the event he suffers a setback related to his prior neck injuries.

ESPN