A person familiar with the negotiations confirmed to The Associated Press that Smith was meeting with the Dolphins. The person spoke to the AP on condition of anonymity because the team has not publicly discussed Sunday's meeting.
Flynn left South Florida on Sunday morning, but a deal with the Dolphins remained a possibility, said his father, Alvin.
Garrard, a starter for Jacksonville from 2005 to 2010, didn't play last year. He was released five days before last year's opener by the Jaguars, then underwent back surgery in October.
But it was Smith's turn on Sunday
Smith struggled early in his career but threw for 3,150 yards and 17 touchdowns with only five interceptions last season as San Francisco went 13-3 and made the NFC title game after an eight-year playoff drought. He orchestrated six comeback wins, four on the road.
All were also on hand for Flynn's 5 1/2-hour meeting Saturday.
Flynn was a backup the past four years for Green Bay, where his offensive coordinator was Joe Philbin, the Dolphins' new head coach. Flynn has only two career NFL starts, but in last year's regular-season finale he set franchise records with 480 yards passing and six touchdowns to help the Packers beat Detroit 45-41.
The Dolphins have started 16 quarterbacks since Dan Marino retired and are looking to make another change. While incumbent Matt Moore played well last year, there are doubts he's a franchise quarterback. Chad Henne, who started 31 games for Miami over the past three seasons, signed Wednesday with the Jacksonville Jaguars as a backup.
Manning has been rehabbing in North Carolina following a string of neck surgeries, which led Indianapolis to release him.
San Francisco running back Frank Gore, who works out each offseason in Miami, said Sunday he hadn't spoken to Smith. Gore has long supported Smith through the quarterback's up-and-down seven NFL seasons.
"It's crazy," Gore said. "I'm waiting for whatever happens. I know coach Harbaugh and (general manager) Trent Baalke feel good about what they're doing."
Manning's whirlwind free agency tour officially kicked off soon after he bid farewell to the Colts in an emotional press conference.
AP Sports Writers Teresa M. Walker in Nashville, Tenn., Joedy McCreary in Durham, N.C., Pat Graham in Denver and Janie McCauley in San Francisco contributed to this report.