It wasn’t the lingering soreness in his knee that forced Mariners right-hander Hisashi Iwakuma to the disabled list prior to Wednesday’s game against the Phillies.
It was a previously undisclosed shoulder problem — characterized as inflammation — that prompted the move. Iwakuma admitted Wednesday that he’s experienced shoulder problems for his last few starts.
"He just didn’t feel like he was ready to post yet," manager Scott Servais said. "He’s a pro. He’s a veteran. You’ve got to trust those guys about when they think they’re ready.
"We sat down (Tuesday), and he just didn’t think he was going to be able to go in Toronto (for his scheduled start on Thursday)."
The Mariners responded by selecting the contract of right-hander Sam Gaviglio from Triple-A Tacoma after clearing space for Gaviglio on their 40-man roster by shifting injured reliever Evan Marshall to the 60-day disabled list.
Marshall suffered a severely pulled right hamstring on May 5. Gaviglio will serve, at least initially, as a long reliever.
"I don’t know a lot about Sam," Servais admitted. "I’m about to learn a lot about Sam. He’ll give us another arm. Sam will work out of the pen for right now. He can take multiple innings and go from there."
Servais said rookie right-hander Chase De Jong will replace Iwakuma as the starting pitcher for Thursday’s series opener against Toronto at the Rogers Centre. Because of Monday’s open date, De Jong will be pitching on normal rest.
Recently-promoted Christian Bergman, a right-hander, will start Friday’s game. He allowed one run in 3 1/3 innings last Sunday while pitching in relief in a 4-3 victory over Texas. Bergman was 5-0 with a 2.17 ERA in five starts at Tacoma.
Servais said Saturday’s starter has not yet been determined, while lefty Ariel Miranda remains in line to start Sunday’s series finale against the Blue Jays.
Gaviglio, 26, was 2-3 with a 3.31 ERA in five starts at Tacoma. A seven-year pro, he has never pitched in the big leagues.
"It’s a dream come true," he said. "I’ve been waiting for this time for a while now."
Iwakuma suffered a bruised left knee after being hit by a line drive in his May 3 start against the Angels. He said the knee was improving but still sore and, along with his ailing shoulder, had prevented him from his usual between-starts routine.
"It’s not good period," he said. "You get anxious about your next start if you’re not able to do your routine."
The Mariners backdated Iwakuma’s time on the disabled list the maximum of three days, which means he could return as soon as May 17, but the severity of his shoulder ailment is yet to be determined.
Tentative plans called for Iwakuma to return to Seattle for further examination while the Mariners head to Toronto for a four-game weekend series.
Iwakuma is the fourth member to the Mariners’ projected rotation who is now on the disabled list. Felix Hernandez has bursitis in his right shoulder; James Paxton has a strained left forearm; and Drew Smyly has a flexor strain in his left elbow.
"No, I haven’t (ever seen anything like this)," Servais said, "but I’ve said many times this year, and I’ll say it again, they keep playing the games. We’ve got to play our schedule. We’ve got to keep going."
Club officials remain hopeful Hernandez and Paxton could return as soon as the upcoming homestand, but Smyly isn’t expected back before late June at the earliest.
CANO IN LINEUP
Some good news on the injury front: Second baseman Robinson Cano returned to the lineup after leaving Tuesday’s game in the fourth inning because of a strained right quadriceps muscle.
Cano recovered quicker than expected overnight — his status was doubtful after Tuesday’s game — and got clearance to play after testing his quadriceps prior to Wednesday’s game.
While Cano played, the Mariners again chose to not to play designated hitter Nelson Cruz in the outfielder because of concerns regarding his sore left hamstring. Cruz had an RBI single as a pinch-hitter in Tuesday’s victory.
Cano has been hot lately after a slow start. He is batting .321 over his last 20 games through Tuesday with six homers and 17 RBIs.
Three things to note heading into Thursday’s pitching matchup between right-hander Chase De Jong and Toronto right-hander Marco Estrada:
***De Jong has never faced the Blue Jays. Estrada is 1-3 with a 4.13 ERA in four career starts against the Mariners.
***No current Blue Jays have ever faced De Jong in the big leagues.
***Nelson Cruz is 5-for-10 with a homer and two walks in 12 career plate appearances against Estrada. Robinson Cano is 2-for-13, and Kyle Seager is 3-for-11. No other Mariner has more than eight career plate appearances against Estrada.
Double-A Arkansas is scuffling at 12-19 in the Texas League, but two Travelers will carry 12-game hitting streaks into Thursday’s game against Springfield (Cardinals) in Little Rock,
Left fielder Chuck Taylor and first baseman Ryan Casteel are both 18-for-47 (.383) in their streaks.
Taylor, 23, has five doubles, one triple and seven RBIs in his surge while raising his overall slash to .337/.461/.530. He was a fourth-round pick by Arizona in the 2013 MLB Draft whom the Mariners acquired last December in the Rule 5 Draft.
Casteel, 25, has four doubles, one homer and four RBIs in his streak. His overall slash is up to .282/345/.369. He was a 17th-round pick by Colorado in 2010 who signed last July with the Mariners as a minor-league free agent.
It was 21 years ago Thursday — May 11, 1996 — that Jay Buhner went 4-for-4, homered twice and matched a career best with six RBIs in an 11-1 romp over Kansas City at the Kingdome.
Buhner also had six RBIs on May 30, 1991 in an 11-4 victory at Texas.
The Mariners and Blue Jays open a four-game weekend series at 4:07 p.m. Pacific time Thursday at the Rogers Centre. Right-hander Chase De Jong (0-2 with a 6.75 ERA) will oppose Toronto righty Marco Estrada (1-2, 3.14).
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).
Bob Dutton: @TNT_Mariners