Hunter had an ingrown toenail removed and is being given an extra day to recover, which lines him up to pitch on Sunday at Fenway Park. Hammel will start on Saturday.
The day off tomorrow allows for extra rest for everyone in the rotation.
Also, Zach Britton is scheduled to pitch in a simulated game on Saturday at the Ed Smith Stadium complex in Sarasota.
Britton will start extended spring training games on May 10 (45 pitches), 15 (60 pitches) and 21 (75 pitches). He could join an affiliate and start his injury-rehab assignment on May 26.
Britton most likely would make a minimum of two minor league starts, so his removal from the disabled list could come at the beginning of June. However, it hasn't been determined whether he'd join the Orioles' rotation or be assigned to Triple-A Norfolk.
Hitting coach Jim Presley has returned to the club after spending about 24 hours in a hospital while passing his second kidney stone in two weeks.