Stewart will start Tuesday against the Rockies, Ken Gurnick of MLB.com reports.
The 26-year-old has thrown 5.2 innings of relief for the Dodgers so far this year, allowing two runs. In 68 career big-league innings, he has a 4.37 ERA, with strikeout (19.7 percent) and walk (11.4 percent) rates which both fall on the wrong side of league average. He's been good in five starts for Triple-A Oklahoma City this season, posting a 2.08 ERA.