The trade enables Robertson to start with the Marlins and assures left-hander Dontrelle Willis a spot in the Detroit rotation. Robertson started six games and also spent time in the bullpen for the Tigers last season, finishing 2-3 with a 5.44 ERA in 28 appearances.
Detroit manager Jim Leyland said Willis will make the third start of the season. Willis earned the final spot in the rotation. Leyland figured Robertson did not want to be a reliever with the Tigers.
"He probably would have not been a happy camper if it would have worked out that he was in the bullpen," Leyland said. "He's been nothing but a good soldier here over the years. We appreciate everything he's done for us. I think this is a great opportunity for him and it unclogs the issue for us a little bit."
"He is a left-hander, which is something we didn't have in the rotation," Florida baseball operations president Larry Beinfest said "And he brings experience, which is something we're light on also."
Right-hander Clay Hensley, who had been expected to join the Florida rotation after a strong spring, will instead likely pitch out of the bullpen.
Detroit is sending Florida cash as part of the deal for Robertson, who is owed $10 million this year in the final season of a $21.25 million, three-year deal. The Marlins will pay just the $400,000 minimum.
Robertson has a 51-69 record and 4.92 ERA in 202 games over eight big league seasons.
The 22-year-old Voss split last season between Class-A Jupiter and Double-A Jacksonville for the Marlins. In 10 games with Jupiter, he compiled a 2.03 ERA and 10 strikeouts. He was 3-0 with a 2.97 ERA and 36 strikeouts in 30 appearances with Jacksonville.
Robertson pitched for the Marlins briefly in 2002 before being traded to Detroit for Mark Redman, who helped Florida win the 2003 World Series.