PITTSBURGH -- Already plagued by injuries this season, the Pirates had to put their Opening Day starter on the shelf on Saturday afternoon.

Pittsburgh placed right-hander Jameson Taillon on the 10-day injured list with a right elbow flexor tendon strain. Taillon will be shut down from throwing for four weeks, director of sports medicine Todd Tomczyk said. He will get a second opinion from Dr. David Altchek, who performed his Tommy John surgery in 2014, but the initial exam revealed no concerns with his ulnar collateral ligament.

“I’m obviously not exactly happy or pleased with anything, but I guess it could be worse,” Taillon said. “Having a history in that area, I was kind of beating myself up over it and I was kind of worried, so to hear that's 100 percent, the bone where they drilled the hole for the surgery and everything is 100 percent, that was a big sigh of relief.”

That was maybe the only positive aspect of Saturday’s news for Taillon, but the 27-year-old -- who has already overcome Tommy John surgery, a hernia operation and most recently cancer in his young career -- is determined to work through his latest setback. He won’t be able to compete on the mound for at least a month, but he was already talking Saturday about ways he can get better and prevent this from happening again.

“If there’s anybody that you are going to bet on coming back,” Pirates manager Clint Hurdle said, “it would be Jameson.”

Taillon, coming off a breakout 2018 season, is 2-3 with a 4.10 ERA in 37 1/3 innings over seven starts. He said his forearm had been bothering him since Spring Training, but he was able to manage the pain until his start in Texas on Wednesday. He said his curveball, his best pitch, began to irritate his throwing arm. He shook off curveball signs late in that outing and wound up giving up home runs on the fastballs he threw instead.

“That’s where it starts becoming an issue and starts affecting the team,” Taillon said.

Taillon woke up more sore than normal on Thursday, and he was still sore on Friday. Finally, he reported the issue to Pittsburgh’s medical staff and underwent an MRI.

“I’d just been kind of fighting with the idea of, ‘I’ll manage it on my own until it gets, hopefully, better, then I won't have to bring it up,’” Taillon said. “And if it gets worse, you know, I have to hit a point where I have to say something.”

Taillon joins starter Chris Archer, left fielder Corey Dickerson, outfielder Lonnie Chisenhall, reliever Nick Burdi, catcher Jacob Stallings and shortstop Erik Gonzalez on the injured list. The latest round of injuries to the Pirates' rotation, the backbone of the team, is perhaps most concerning. Archer is eligible to return on Tuesday but may need a few more days to get back on the mound.

That leaves Pittsburgh with three healthy starters from their Opening Day rotation: Trevor Williams, Jordan Lyles and Joe Musgrove. Left-hander Steven Brault will step out of the bullpen to start against the Rangers on Tuesday, and Nick Kingham will follow suit to pitch on Wednesday at PNC Park. Brault and Kingham competed for the final spot in the Pirates’ rotation, which ultimately went to Lyles, and they have pitched sporadically in relief this season.

The Pirates don’t have much Major League-ready rotation depth waiting in Triple-A. Top prospect Mitch Keller has put up a 3.48 ERA with 38 strikeouts in 31 innings over six starts for Triple-A Indianapolis, but the Bucs don’t want to harm his development by rushing him to the Majors. Right-hander J.T. Brubaker, who might have been considered for a callup, is sidelined with a strained forearm.

Hurdle said the Pirates have had several conversations this season about the idea of using an opener, but he indicated that strategy remains a backup option.

The Pirates replaced Taillon on their pitching staff by selecting the contract of left-handed reliever Tyler Lyons from Triple-A Indianapolis. The veteran lefty signed a Minor League contract with the Bucs during the offseason and reported to Triple-A to begin the season. He had a 3.18 ERA with 12 strikeouts in 10 appearances for Indianapolis. Lyons can pitch multiple innings, a trait Hurdle said the Pirates were looking for with two established starters out.

“I know it’s never easy to get here. To be given the opportunity to come back, it’s something that you don’t take for granted,” Lyons said. “Just excited to have an opportunity to get back on a big league field again.”

The Pirates cleared a spot for Lyons on their 40-man roster by designating outfielder JB Shuck for assignment. To fill Shuck’s spot on the active roster, Pittsburgh recalled reliever Dovydas Neverauskas from Triple-A. Shuck hit .213 with a .595 OPS while playing all three outfield spots -- and even pitching in an emergency -- for the Pirates.

The Pirates further shuffled their bench before Saturday’s game against the A’s at PNC Park, activating infielder/outfielder Kevin Newman from the injured list and reinstating him from his rehab assignment while optioning struggling super-utility man Pablo Reyes to Triple-A.

Newman, who missed nearly a month with a lacerated right middle finger, went 7-for-30 in eight rehab games for Indianapolis. He made four starts at shortstop, two starts in left field and two starts in center field. Hurdle said Newman will serve as a backup at shortstop and second base as well as the outfield.

“Any way I can help the team win, any way I can get on the field,” Newman said. “If that’s how it is, I’m ready for it and excited for it. … I’m ready to be put in or start or whatever at any time.”