Tankersley, who will turn 28 in March, posted a 7.50 ERA in 27 games last season, his first action since missing the entire 2009 season with a stress fracture in his left elbow. The former first-round Draft pick has a 4.58 career ERA in 168 appearances, all with the Marlins, striking out 115 batters in 118 innings.
Tankersley became a free agent in October after refusing a Minor League assignment.
He will compete for a job in a bullpen that, after losing left-handers Hisanori Takahashi (Angels) and Pedro Feliciano (Yankees) to free agency, no longer possesses a dedicated lefty specialist. Currently, the Mets have only two other lefty relievers -- Pat Misch and Oliver Perez -- on their 40-man roster, neither of whom have enjoyed any consistent big league success in recent years. Eric Niesen and Roy Merritt could also make the bullpen as lefties, barring another free-agent acquisition.
The bullpen, then, is finally beginning to take shape. In addition to Tankersley, the Mets have also acquired right-handers D.J. Carrasco, Taylor Buchholz and Rule 5 Draft selection Pedro Beato this offseason, filling spots behind closer Francisco Rodriguez and setup man Bobby Parnell.