Boston Red Sox pitcher Eduardo Rodriguez described his experience with covid-19 as feeling “like I was 100 years old.” Now, the 27-year-old left-hander will miss the 2020 season while recovering from a heart issue related to the illness.

Rodriguez, who tested positive for the coronavirus July 7, was ready to return July 18, but, five days later, an MRI revealed what turned out to be myocarditis, an inflammation of the heart that has been shown to be a complication of a virus that can affect the kidneys and heart as well as the lungs.

“The heart is the most important part of your body, so when you hear that — the first time that I heard it — I was kind of scared,” Rodriguez said (via Mass Live) July 26. “Now that I know what it is, it’s still scary, but now I know exactly what it is. Just talk to my mom, talk to my wife, they know what I have and everything. Now we just gotta take the rest. That’s hard, but you gotta take a rest.''

The pitcher, who had been scheduled to start Opening Day for the Sox, underwent further tests Friday that determined his condition had not subsided. Myocarditis, according to the Mayo Clinic, is an inflammation of the heart muscle that can “affect your heart muscle and your heart’s electrical system, reducing your heart’s ability to pump and causing rapid or abnormal heart rhythms.”

“Health-wise, I feel normal,” Rodriguez said July 26. “They just told me to take a rest for a week and wait to get the next tests and see what it is. Emotional-wise, it feels really hard because when I got here, I was supposed to start getting ready [to pitch].”

The Red Sox’ chief baseball officer repeatedly described Rodriguez’s condition as “mild” and he was returning to his Florida home to recover.

“In the course of monitoring Eduardo after his return, we discovered that he was showing evidence of myocarditis, which is an inflammation of the heart, and fortunately, the severity of that complication looked mild,” Chaim Bloom said (via the Associated Press) Saturday.

“We were optimistic that it would resolve in short order and that we would be progressing back to pitching. As we’ve continued to monitor it, it has not resolved. It is still there."

Bloom added that the team is “confident that he is going to make a full recovery and that his long-term prognosis is excellent,” but the sport’s shortened season didn’t leave enough time for him to fully recover and pitch.

“Here’s one of the best pitchers in the game last year and he’s not able to perform on the field,” Red Sox Manager Ron Roenicke said (via the AP). “You’re more at risk when you’re older, but it hits the young pretty hard, too, at times. And Eddie just, unfortunately, is one of those guys that it hit hard, and to get to lose an entire season, it’s pretty rough on anybody.”

Rodriguez said he had no idea where he had caught the virus and that it took over a week for him to feel better. His wife also came down with covid.

“I felt like I was 100 years old. My body was tired all the time,” he said July 19. “Throwing up. Headaches. Like I said, all the symptoms.”

Rodríguez was a career-best 19-6 with a 3.81 ERA last season. While there is optimism about Rodriguez’s 2021 prospects, much remains unknown about coronavirus and covid.

“This case, while it’s something that is persistent, is not something that has that has impacted or damaged the functioning of his heart,” Bloom said. “Now myocarditis following covid, it is obviously not something that the medical community has a lot of data on because the virus itself is new, much less in an athlete.”