Smith elected free agency Thursday, Matt Weyrich of The Baltimore Sun reports.
The Orioles placed Smith on the 15-day injured list Friday due to a groin strain, Andy Kostka of TheBaltimoreBanner.com reports.
Smith (4-1) took the loss Sunday versus the Astros, allowing two runs on two hits and striking out two over one inning.
Smith (3-0) earned the win Wednesday over the Blue Jays, striking out two over a perfect inning.
The Orioles selected Smith's contract from Triple-A Norfolk on Thursday.
Smith signed a minor-league contract with the Orioles on Friday, Rich Dubroff of BaltimoreBaseball.com reports.
The Marlins released Smith on Thursday.
The Marlins designated Smith for assignment on Friday.
Smith (1-0) picked up the win Thursday, striking out two in a perfect 10th inning during the Marlins' victory over the Rockies.
The Marlins acquired Smith from the Rays on Wednesday in exchange for cash considerations and selected Smith's contract from Triple-A Jacksonville, Marc Topkin of the Tampa Bay Times reports.