Starting rotation:
2018: Chris Sale, David Price, Rick Porcello, Brian Johnson, Hector Velazquez
2019: Chris Sale, Nathan Eovaldi, Eduardo Rodriguez, Rick Porcello David Price
In 2018, the Red Sox opened up the year with Brian Johnson and Hector Velazquez in their rotation due to injuries to Eduardo Rodriguez and Drew Pomeranz. When Rodriguez came back he was solid but Pomeranz struggled badly, leaving a hole in that fifth spot. Eventually, the Red Sox filled the hole with postseason hero Nathan Eovaldi.
Now in 2019, Eovaldi will look to build on the second half from last year in his first full season with Boston. Rodriguez will look to take the next step. Overall, this is a very solid rotation that will be the key to their success.
Bullpen:
2018: Craig Kimbrel, Matt Barnes, Carson Smith, Bobby Poyner, Heath Hembree, Marcus Walden, Hector Velazquez
2019: Matt Barnes, Ryan Brasier, Heath Hembree, Colten Brewer, Brandon Workman, Tyler Thornburg, Hector Velazquez
The one major difference here obviously, is the loss of Craig Kimbrel. Barnes, Brasier, and Hembree will handle most of the high leverage spots while Thornburg and Workman have the chance to try and prove they still belong on the roster. Brewer will look to prove he can handle a high leverage spot and has more upside than most of the other guys in the bullpen. This part of the team is by far the biggest question mark.