The Miami Marlins have activated right-hander Henderson Alvarez from the 60-day disabled list to start Thursday night against the Atlanta Braves.
The Marlins optioned right-hander Tom Koehler to Triple-A New Orleans.
Alvarez, who has been recovering from right shoulder inflammation, will make his debut with Miami. He was 9-14 with a 4.85 ERA for Toronto last season. He came to Miami in the November 2012 trade that sent Josh Johnson, Jose Reyes and others to the Blue Jays.
Koehler, a rookie right-hander, was 1-5 with a 4.70 ERA in 16 games, including 10 starts. He gave up three runs, two earned, in five innings of the Marlins' 11-3 loss to the Braves on Tuesday night.
The team transferred outfielder Matt Diaz to the 60-day disabled list.