Sanchez, who is the 18th ranked top prospect by MLB.com, has gone 0-3 in eight games (six starts) with a 4.19 earned run average this season for the Bisons.
The 22-year-old was selected in the first round of the 2010 MLB Amateur Draft by the Blue Jays.
Toronto also selected the contract of pitcher Esmil Rogers from Buffalo, recalled shortstop Ryan Goins, optioned outfielder Darin Mastroianni and catcher Erik Kratz and designated pitcher Brad Mills for assignment.
Rogers has appeared in 16 games for the Blue Jays this season, his sixth in the majors, with a 6.97 ERA. Goins has hit for a .150 batting average with one RBI and a home run in 24 games this year.
Mastroianni has homered and driven in two runs across 21 games for the Twins and Blue Jays this season, while Kratz has three home runs, 10 RBI and a .198 batting average in 34 games.
Mills, who was claimed off waivers from Oakland, played just one game for the Blue Jays, where he gave up eight runs in two innings of work on Monday