The Washington Nationals boast one of the best pitching staffs in the league, but there are a few durability concerns, both in the rotation and bullpen.
Max Scherzer battled injuries throughout most of 2017 and Stephen Strasburg has proven to be extremely injury-prone throughout his career. In the bullpen, Sean Doolittle, Koda Glover, and Shawn Kelley have all dealt with various injuries throughout their careers.
In addition to a few durability concerns, the Nats are currently in need of a fifth starter. Considering these two issues, they must build up their pitching depth.