"We want him to be able to enjoy his experience there, be able to pitch, not have to worry about coming out of it three days later," Francona said. "We may redo that, but we should have it [figured out] tomorrow."
The Indians don't want any uncertainty regarding the rotation depending on whether Masterson -- who's 10-7 with a 3.72 ERA -- pitches during the Midsummer Classic at New York's Citi Field.
"We want it concrete regardless," Francona said.
The rotation already contains one question mark in the form of Zach McAllister, who made his first rehab start on Saturday as part of his recovery from a sprained right middle finger. McAllister, who hasn't pitched since June 2, compiled a 4-5 record and 3.43 ERA over 11 starts before landing on the disabled list.
McAllister is expected to make at least one more rehab start. The Indians haven't ruled out inserting him into the rotation at the start of the second half, though that seems unlikely.
"Things would have to go really well," Francona said. "And they might, but we'll see."
Mark Emery is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.