"I think he probably wanted to come back and pitch," Francona said. "But I think we all thought one more start would be beneficial."
In the meantime, Friday's start is somewhat up for grabs. Josh Tomlin, who allowed four earned runs over 4 1/3 innings on Sunday at Detroit -- will likely get another chance. But Zach McAllister, currently in Columbus, is another option.
The only certainty is that it won't be Masterson, who will fly into Minneapolis to spend time working with pitching coach Mickey Callaway before returning to pitch for Columbus on Friday.
Alex M. Smith is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.