Sanchez was promoted to Double-A Jacksonville on Tuesday, Sam Dykstra of MiLB.com reports.
The Marlins managed Sanchez's workload with a late start to the season, but he'll move up after just two starts for High-A Jupiter. He didn't pitch particularly well in those two starts, allowing six runs in 11 innings while striking out just six batters, but the Marlins may simply have been treating those as a quick tune-up before he spends the bulk of the season with Jacksonville. Over his five-year minor-league career, the 20-year-old has a 2.60 ERA with a 21.4 percent strikeout rate and 4.9 percent walk rate.