Toronto optioned the 24-year-old right-hander to Class A Dunedin on Sunday. The Blue Jays plan to recall him to start against the Baltimore Orioles on Aug. 31.
Sanchez is 12-2 with a 2.99 ERA, fifth-best in the American League. He has made 24 starts and thrown a career-high 156⅓ innings. He likely will not pitch in the minors.
"We've talked a lot about this over the year," Blue Jays general manager Ross Atkins said. "Not just over the last month, but as good as Aaron has become, we all along thought at some point we'll have to manage his workload. That's what this is about. He'll come right back in the rotation."
Sanchez has struck out 132, and opponents are batting .230 against him. Left-hander Aaron Loup was recalled from Triple-A Buffalo and will pitch out of the bullpen.
Sanchez pitched three hitless innings Saturday then allowed Cleveland to tie the score with a five-run fourth and was pulled.
"Making this move was something we tried to stay away from, talking about innings being a concern," Sanchez said. "I still have to get ready. It's not like my season's over. It's normal work when I go down there. Nothing changes for me.
"The last few starts have been on seven or eight days' [rest]," he added. "As a pitcher there's adjustments you have to make. I don't think I've forgotten how to pitch."