Mengden will be recalled to start Saturday against the Red Sox, John Hickey of the Bay Area News Group reports.
Although Mengden was not added to the A's expanded September roster right away Friday, he will come up to start Saturday opposite Rick Porcello, presumably pushing Zach Neal to the bullpen. The 23-year-old Mengden enjoyed some initial success upon arrival to the big leagues in June but he quickly unraveled, and the blowup potential against Boston will understandably scare off many prospective owners.