The news came early Saturday in a terse release from the Mariners that applied another major blow to their depleted rotation.
Right-hander Hisashi Iwakuma, 36, is expected to miss four-to-six weeks because of shoulder inflammation. He was examined Friday by Dr. Edward Khalfayan, the club’s medical director, in Seattle.
Iwakuma said he experienced shoulder discomfort in recent starts before the Mariners moved May 10 to place him on the 10-day disabled list. He is 0-2 with a 4.35 ERA in six starts.
"I’m optimistic," manager Scott Servais said. "I’m hoping it’s more toward the four-weeks side of things, but you never know. It’s kind of surprising. I wasn’t expecting it to be that long."
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Losing Iwakuma for an extended period is the latest in a series of problems for a rotation struggling to find equilibrium. Four of the club’s five projected starters are on the disabled list.
Only lefty James Paxton appears to be moving toward an imminent return. He was diagnosed as having a strained forearm muscle after a May 2 start against the Angels but is tracking toward a return in 10-14 days.
Long-time ace Felix Hernandez hasn’t pitched leaving an April 25 start at Detroit because of what was subsequently diagnosed of bursitis in his shoulder. He played catch twice earlier this week but still felt discomfort.
Hernandez is expected to resume playing catch within a day or two but, even in a best-case scenario, appears unlikely to return before early June.
Lefty Drew Smyly, a major offseason acquisition, hasn’t pitched since suffering a strained flexor in his elbow in late March. Club officials hope he might be ready to return by late June.
"It’s challenging," Servais said. "I’m not going to lie. It’s something you can never plan for, but Toronto is having to go through a similar thing. They’ve got two or three guys out of their rotation. It does happen.
"You’re hoping you can just somehow stay afloat until everybody does get healthy."
CANO SITS AGAIN
Second baseman Robinson Cano tested his strained right quadriceps muscle by taking batting practice prior to the game but remained absent from the starting lineup for a third straight game.
"Trying to land on that front leg was a little tender," Servais said. "We’ll do the right thing. I want him back as close to 100 percent versus sending him out there at 50-60 percent and then we have another setback and we lose him for longer.
"It’s a delicate balance. Obviously, we know what he means to our team and our lineup. But thinking bigger picture here, we don’t want to lose him for an extended period of time."
Cano suffered the injury Tuesday in Philadelphia while running out a double and left the game in the fourth inning. He returned Wednesday to the lineup but aggravated the injury while running out a grounder in the ninth inning.
It underscored the Mariners’ concerns with their rotation that they chose to clear space Saturday for right-hander Ryan Weber by designating veteran reliever Jean Machi for assignment.
Machi had a 1.17 ERA in five outings since his May 2 promotion from Triple-A Tacoma, where he didn’t allow a run in eight appearances. It’s hard to justify dumping Machi on merit.
"It’s a lot of roster mechanics," Servais said. "A lot of it comes back to being very thin at starting pitcher right now. We’ve got to keep as many guys, who can start a game for us, as possible. That plays into these decisions."
Machi, 35, is a short reliever who pitched 2 1/3 innings Friday, which meant he was unlikely to be available Saturday or Sunday. By Monday, the Mariners anticipate Steve Cishek will be ready to return from the disabled list.
The Mariners have seven days to reach a resolution on Machi either through a release, a trade or, if he clears waivers, sending him back to Tacoma on an outright assignment.
Three things to note heading into Sunday’s pitching matchup between left-hander Ariel Miranda and Toronto right-hander Aaron Sanchez:
***Miranda has never faced the Blue Jays. Sanchez is 2-0 with a 1.72 ERA in five career games against the Mariners, including two starts.
***No current Blue Jays have ever faced Miranda in the big leagues.
***Jean Segura is 2-for-4 in his career against Sanchez, while Kyle Seager is 2-for-6 with a home run. But Nelson Cruz is just 1-for-7, and Robinson Cano is 0-for-6.
Lo-A Clinton right-hander Danny Garcia had 11 strikeouts Friday in an 8-3 victory over Great Lakes (Dodgers). He gave up three runs and three hits while walking one in a 91-pitch outing.
Garcia is 2-3 with a 5.13 ERA in seven starts. He was a 15th-round pick last year in the MLB Draft.
It was 21 years ago Sunday — May 14, 1996 — that the Mariners failed to get a hit in a 2-0 loss to New York right-hander Dwight Gooden at Yankee Stadium. Gooden walked six in a 134-pitch performance.
The final out was a popup by Paul Sorento to rookie shortstop Derek Jeter, whose No. 2 is being retired Sunday by the Yankees.
It was the second of three no-hit losses for the Mariners in their 41 seasons.
California’s Mark Langston and Mike Witt combined for a no-hitter on April 11, 1990 in Anaheim; and Philip Humber of the Chicago White Sox pitched a perfect game on April 21, 2012 at Safeco Field.
The Mariners and Blue Jays conclude their four-game weekend series at 10:07 a.m. Pacific time Sunday at the Rogers Centre when lefty Ariel Miranda (3-2 with a 5.20 ERA) opposes Toronto right-hander Aaron Sanchez (0-1, 4.05).
Sanchez will activated from the disabled prior to the game. He hasn’t pitched since April 30 because of a split nail on his middle finger.
The game can be seen on Root Sports Northwest and heard on 710 ESPN and the Mariners Radio Network, including mariners.com (for subscribers to MLB.tv).
The Mariners open a seven-game homestand Monday with the first of three games against Oakland. The homestand concludes with four games against the Chicago White Sox.
Bob Dutton: @TNT_Mariners