"We've talked to Felix about how the first one went and we want to make sure he's ready to go when he comes out here at the big league level," Servais said before Saturday's game. "We'll see how it goes tomorrow, but that's what was discussed yesterday and that's best thing for him at this time."
Hernandez allowed five runs on four hits with two walks and three strikeouts in his first rehab start for Triple-A Tacoma on June 6. His second rehab start is scheduled with Tacoma on Sunday, when he'll throw roughly 65 pitches.
"We're trying to plan for the long haul, [we] don't want to rush Felix back," Servais said. "[We don't want], 10 days from now or two weeks from now, he's not feeling right and now we have to skip him. So let's make sure he's completely right, on top of his game, and once he gets in, he can get in and go."
Hernandez was 2-2 with a 4.73 ERA in five starts prior to the injury.
Retaining Hernandez's health is the primary reason for not rushing him back, but the recent success of the Mariners' patchwork rotation doesn't hurt, either. Mariners starters are 8-2 with a 3.42 ERA in the last 12 games, allowing two or fewer runs in eight of those, and going at least five innings in all 12.
Iwakuma inching closer to return
On Sunday, Hisashi Iwakuma will throw his second simulated game since landing on the 10-day disabled list with inflammation in his right shoulder. The Mariners plan to have him make a rehabilitation start next week.
"I'm anxious to see how that looks," Servais said of Iwakuma's simulated game. "I know his bullpen [session] the other day went much better, [pitching coach] Mel [Stottlemyre Jr.] said it was the best he's seen him all year so far."
Iwakuma had an 0-2 record and a 4.35 ERA in six starts before heading to the disabled list. His return projects to be in late June.
• The Mariners called up right-handed reliever Emilio Pagan and optioned right-handed reliever Tyler Cloyd to Triple-A, the club announced Saturday.
Servais said they wanted to get someone who can contribute out of the bullpen immediately.
"[Cloyd] was kind of designed [as] a long guy, a starting pitcher type, with him coming back from Tommy John surgery, so he's not really lined up to go back-to-back days," he said. "Tacoma is in town, so we optioned him back and brought Pagan in. [Pagan] did a good job when he was there. He'll give us a fresh arm tonight if we need it."
• Outfielder Mitch Haniger is in the lineup for Triple-A Tacoma on Saturday and will play only part of the game, according to Servais.
Josh Horton is a reporter for MLB.com based in Seattle.