PEORIA, Ariz. — What was initially diagnosed as a minor issue for Mariners reliever Shae Simmons by the team’s medical staff was confirmed by a MRI.

Simmons, who left Sunday’s game with stiffness in his forearm, has a muscular strain in his right forearm and no structural damage to his surgically repaired elbow.

“The results came back good for him,” manager Scott Servais said. “It’s just a strain in the muscle mass in the forearm. We’ll shut him down for a little time, let it calm down and go from there.”

Simmons has dealt with arm issues the past two seasons dating back to a torn ulnar collateral ligament in February of 2015, which required season-ending Tommy John surgery. The MRI showed no issues with the elbow.

“Nothing related to the ligament or anything like that, from what I understand,” Servais said. “So it’s good for him. He’ll sleep a little easier. And that’s pretty much what the doctors figured.”

Servais wouldn’t put a time frame on Simmons’ return. As a reliever, the time to build arm strength back up won’t be quite as drastic for Simmons, but Servais didn’t want to explore any possibilities.

“We’re just going to be very cautious with him,” Servais said. “You’ve got to calm it down first. So time frame on that, I don’t know.”

Meanwhile, two other right-handed relievers are making progress as they work their way back from offseason surgery.

Tony Zych (shoulder) has been throwing bullpen sessions and will now take the next step later in the week, facing hitters in a live batting practice situation. That means Zych could be in Cactus League games by next week at the earliest.

“Tony is progressing very nicely,” Servais said.

— Steve Cishek (hip) has been playing catch and long toss to build arm strength. The Mariners are starting to anticipate him throwing off the mound.

“He’s gearing up toward his first bullpen,” Servais said. “He’s probably a little ways from that yet, probably 10 days to two weeks from a bullpen and letting it rip there. But the arm strength is coming along good. Both are positives, we’re moving in the right direction with those guys.”

With that projected schedule, Cishek will not be read for the opening day roster, which is something the Mariners have anticipated.

“I think coming into this camp, no secrets here, we projected that he might start the season a little late,” Servais said. “So we’re still on that schedule.”