NEW YORK -- The A's announced a shakeup in their starting rotation, with Sean Manaea moving up a day to pitch Friday's series opener against the Yankees in place of Kendall Graveman.
In addition, Jharel Cotton will be called up to start Saturday afternoon.
Graveman is experiencing more soreness in his throwing shoulder, manager Bob Melvin said before Friday's game. The right-hander is scheduled to see a doctor in the Bay Area, and both he and Jesse Hahn (strained triceps) are likely to hit the disabled list. Neither pitcher is with the team in New York.
Graveman, the A's Opening Night starter, seemed fine coming out of his last start, but Melvin said he experienced discomfort in his shoulder following a recent bullpen session. Graveman missed 10 games on the DL earlier this season with a shoulder strain, and given that a problem has surfaced for a second time, Melvin said: "This DL (stint) is gonna take longer, if indeed he goes on the DL."
There was a mild bit of good news in that Hahn underwent an MRI for his triceps issue that showed no structural damage.
Cotton arrived at Yankee Stadium about 4:15 p.m. local time, saying one of his focuses while down with Triple-A Nashville was pitching inside more effectively.
"It could help my changeup, open up the outside corner," Cotton said.
Melvin said the team would likely wait a day or two before announcing Hahn's replacement in the rotation.