FORT MYERS, Fla. — It keeps getting worse for the Red Sox.

In the past two days, the Yankees added All-Stars Josh Donaldson and Anthony Rizzo while the Blue Jays added All-Star Matt Chapman. The Sox haven’t made any substantial additions but are now subtracting one of their best players, Chris Sale, from their Opening Day roster.

Chief baseball officer Chaim Bloom announced Wednesday morning that Sale had suffered a stress fracture in his right rib and would not be ready to start the season. He hurt himself throwing a live batting practice session that he streamed on Instagram on Feb. 24, when MLB owners were still locking out the players, who were not allowed on team premises nor were allowed to communicate with team officials and had to train on their own.

For the third straight year, Nathan Eovaldi will be Boston’s Opening Day starter when the Red Sox face the Yankees in New York on April 7.

Sale was training at his alma mater, Florida Gulf Coast University, when he got hurt.

“After that, felt a little side discomfort, nothing too crazy,” he said. “I didn’t think anything of it. Over the next probably handful of days, not only did it stick around, it felt like it kind of got worse. I actually reached out to my college coach, Coach Dave Tollett over at FGCU, he got me in touch with Dr. Patrick Joyner, who’s in the area, and I got an MRI, CT-scan, X-ray, the whole thing and that’s when they saw in the MRI was a stress fracture, I believe. It’s the eighth rib, so, yeah, took some medicine, tried to get some of the inflammation out of there and now we’re just kind of playing the waiting game, waiting for a bone to heal.”

Sale said he won’t see a doctor until it’s been six to eight weeks since the initial injury. That places him in the doctor’s office sometime in early April for a follow-up on what comes next.

Asked for a timetable on when he can pitch again, Sale said, “I don’t have any idea. That’s just like, if you break your arm, you’re going to go to the doctor and he’s going to tell you six to eight weeks. And in six to eight weeks you’ll go back to the doctor and he says you’re either done and you can start doing this, or you have X, X and X left. I’m just waiting until that next doctor’s appointment to get here and he tells me what’s next.”

Sale was particularly discouraged because he’s made just nine starts in the last two years while recovering from a shoulder issue at the end of 2019 and Tommy John surgery he underwent in 2020.

“But the way my body was feeling before all this happened, I was throwing off a mound a lot better than I have been at that time in previous years,” Sale said. “I had a little more to prove coming into spring training. I wanted to be stronger.”

He was playing catch with Red Sox righty Nick Pivetta every day and said he may have overworked himself.

“The one thing I really focused on this offseason was long-toss because I needed arm strength,” Sale said. “I took two years off from pitching and the one thing I noticed the most I was missing was arm strength because it just wasn’t out there. To answer your question (about overworking), in short, yes, because I put in a lot of work to prepare myself for this moment.”

Had the players not been locked out and Sale had been training at the Sox’ facilities under the watchful eyes of their training staff, would this injury would have occurred?

“Good question,” Bloom said. “Obviously, we would’ve loved to have had him here.”

Said Sale, “This a freak accident. Would it have happened if I was training here the whole offseason? That’s an unanswerable question so why even waste time on that? I was given a set of circumstances Dec. 1 (when the owners locked out the players) and I had to play with what I had. And that’s exactly what I did.”

The lockout unquestionably made things difficult for both the teams and players, though teams were responsible for providing detailed plans to players before Dec. 1.

Now the Red Sox have to go into the season without their ace.

“We’re talking weeks before he can start throwing again,” Bloom said. “You need to build him up. As you saw, he was already pretty well along before this happened, so the build-up shouldn’t be too long when we’re able to get him back, but we don’t know when that will be.”

The starting rotation should now include Nathan Eovaldi, Nick Pivetta, Tanner Houck, Garrett Whitlock and Rich Hill, though Michael Wacha could also factor into that mix.

The Sox are stretching out both Houck and Whitlock, but said they aren’t committed to specific roles with them.

Bloom was asked if he’d be more aggressive in pursuing more pitching with Sale’s injury.

“It’s always something that we’re looking to supplement,” Bloom said. “That’s actually why we went out and got some of the guys we did before the lockout because we wanted to have different options.”

WITH QUESTIONS swirling over player availability in New York and Toronto because of vaccine mandates, several Red Sox players have announced that they are vaccinated.

Sale is not one of them, he said Wednesday.

“We’ll see what happens when that rolls around,” he said.

THE RED SOX made their two-year deal with lefty Jake Diekman official. He’ll receive $8 million in total. The 35-year-old had a 3.86 ERA with the A’s last year.