"He's somewhere," Twins manager Ron Gardenhire said. "We'll let you know."
The Twins have several options at Rochester, including top prospects Alex Meyer and Trevor May. Meyer is scheduled to start for the Red Wings on Saturday, while May is slated to start Sunday.
May is considered much more likely than Meyer because Meyer has been on a pitch-count limit this season as a precaution stemming from shoulder issues last season. May, who is on the 40-man roster unlike Meyer, would also be pitching on normal rest, as his last start with Rochester came Monday.
The Twins could also opt to bring up left-hander Kris Johnson, who last started Friday and is scheduled to start Monday for Rochester. Johnson has already made three spot starts with Minnesota this year, going 0-1 with a 4.73 ERA.
Fellow lefty Tommy Milone, who was acquired from the A's in the trade that sent Sam Fuld to Oakland on July 31, last started with Rochester on Tuesday, so he's not expected to be called up to pitch on short rest.
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. This story was not subject to the approval of Major League Baseball or its clubs.