Sanchez is expected to throw from a mound on Wednesday and Saturday in Dunedin, Fla. He will then be re-evaluated before a timetable for rehab starts is determined.
"I didn't think he was going to take this long, but it's not my arm either," said Blue Jays manager John Gibbons on Saturday. "He's got to build up a few innings so I've got to believe at least two (rehab starts). He'll be pitching there during the (All-Star) break. We may run him for two innings that first go around."
Sanchez (5-4) was placed on the 15-day disabled list on June 6 and has not pitched since an eight-inning outing against the Houston Astros on June 5.
"This (injury) snuck up on him a little bit, and we're being cautious," said Blue Jays pitching coach Pete Walker last weekend. "We'll stay on top of it in the second half of the season, but we expect him to be really good for us."
The Blue Jays are targeting a mid-July return for the 22-year-old.