"We talk about probably next Sunday, but I don't know yet," Sanchez said.
Sanchez had been scheduled to throw a bullpen session on Thursday, but he ended up long tossing instead and expected to throw a side session on Friday.
Tigers manager Brad Ausmus offered no timetable as to when Sanchez may return.
"There's a day in mind, but we have to wait and see," the skipper said.
Matt Slovin is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.