Redmond expects Alvarez to continue to "ramp up the pitches with some changeups in there and start a progression and building arm strength back up."
First baseman Logan Morrison, who was moved to the 60-day disabled list as he recovers from knee surgery, started to run. Redmond called it a "good sign."
Joe Mahoney, claimed from the Orioles this offseason and hoping to fill in at first with Morrison on the DL, started Friday night in a rehab game with the Class A Advanced Jupiter Hammerheads.
Mahoney opened the season on the 15-day DL, retroactive to March 22, with an intercostal strain. He played in an extended spring training game on Wednesday, going 1-for-4 with a home run and two strikeouts.
According to Redmond, there are no timetables for their returns. The organization will continue to evaluate how each feels moving forward.
"That's good, guys are progressing and hopefully getting them on their way to health," Redmond said. "That's the key."
Christina De Nicola is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.