The Boston Red Sox had a pretty rough season last year. One of the biggest issues was from pitchers Chris Sale and Nathan Eovaldi struggling to stay on the field due to multiple injuries. 
Chris Sale
Comparing championship year 2018 to the Red Sox’s loss in 2019, Sale’s win-loss stat went from 12–4 to 6–11.  His ERA from 2018 was 2.11, very different from the 4.40 stat in the 2019 season. In August 2019 he was knocked to a 10-day injury list because of an inflamed elbow. Masslive reported that, “The left-handed pitcher missed the final six weeks of the 2019 season (39 games) because of elbow inflammation.” 
In an article from mlb.com/news, it was reported that, “Dombrowski said Saturday’s MRI made it clear that the inflammation came from Sale’s start against the Indians on Tuesday, and not an injury he’s pitched through this season. Sale told the Red Sox he didn’t feel anything during that start, when he struck out 12 over 6 2/3 innings against the Indians, and reached the 2,000-strikeout mark faster than any pitcher in history.” In the same Masslive article from Feb. 16, 2020, they stated, “Sale threw off a mound six or seven times this offseason. He said he prepared for spring training like he normally does … ‘Started flipping some breaking balls and getting after it a little bit,’ Sale said.” The article goes on with Sale talking about how much better he feels, “I feel better than I have in a long time, actually,” Sale said. “I’ve never taken that time off before. I don’t know if since I started baseball if I’ve had that time off. It’s obviously something you don’t want to go through. That was miserable. But there’s silver linings with everything. You try to take the positives in every crappy scenario that comes up. I think that time off helped my entire body regenerate. My shoulder, my elbow, my forearm … Every muscle in my body got a really long break in trying to heal. I think in the end, it will help me out in the long run.”
 
Nathan Eovaldi
 
Eovaldi signed to the Red Sox in 2018 for four years for $68 million. From a 3.33 ERA in 2018 to a 5.99 ERA in 2019, he wasn’t able to play most of the season. On July 15, 2019, NESN reported that, “Eovaldi has been on the injured list since April after undergoing surgery to remove loose bodies from his elbow. He’s slowly been making his way back and will be used out of the bullpen once he comes back.” He was placed on a 60-day injury list. Another NESN article from Feb. 15, 2020 reported, “But in an appearance on NESN’s ‘Red Sox From Ft. Myers,’ Eovaldi explained to Tom Caron that he thinks people might be sleeping on the Red Sox and their rotation. ‘I almost feel like this is one of those years where everybody is sleeping on us,’ Eovaldi said. ‘We end up trading Mookie and David, but we still have Sale, myself, Eddie, the way he threw the ball last year (was) outstanding. We picked up Perez. I think a lot of people are sleeping on us and we’re going to come out and surprise a lot of people this year.’ ”