Toronto placed the rookie starter on the 15-day disabled list following Sunday afternoon's 13-5 victory over the Red Sox. The move was backdated to June 6, which means Sanchez technically could miss just two starts, but it's too early to say whether he'd be able to make a start Sunday against the Orioles.
There's a good chance Sanchez will need a little bit more time than that. Washington right-hander Stephen Strasburg missed three weeks with a "slight strain" of his lat in 2013, and Roy Halladay missed six weeks in 2012 but he dealt with a more severe strain.
"We don't know, we don't think it's a big deal," Blue Jays manager John Gibbons said when asked for an estimated recovery time. "It was more of, he's still a little tender, there's no use pushing it. He's too valuable to us, and if you keep aggravating it, it might eventually turn into something longer."
Right-hander Scott Copeland will join the rotation until Sanchez is able to resume his starting role. Copeland is scheduled to make his second start of the year on Tuesday against the Mets and in all likelihood also will get the ball for Sunday's game against Baltimore.
Copeland's first big league start was on Wednesday against the Marlins, and the Blue Jays couldn't have asked for a better performance. The 27-year-old allowed one run on six hits with four strikeouts over seven strong innings.
"Copeland had a good one that last one, so hopefully he can keep that going," Gibbons said. "That definitely made the decision easier, I'll tell you that."