Should a starter go down, the Nationals will need to pluck from a less established pool of fill-ins than they did last season, when Tanner Roark was ready to slide in.
The team continues to expand its roster with two more additions.
The Nationals officially called up their Saturday starter, and optioned WHO.
The Nationals recall Cole, who is likely to start Saturday against the Cubs.
The Nationals most big-league ready starting pitching prospect is bouncing back well from a tough debut.
He tossed three scoreless innings to earn his first major league save on Friday.
Fister has been off to an odd start this season; his home runs and walks are up, and velocity down.
With the bullpen needing reinforcements and Reed Johnson injured Tuesday, the Nationals made moves to stabilize their roster.
The Nationals 23-year-old pitching prospect had a tough first outing, but says he will learn from the experience, not dwell on it.
Scherzer could slot back into the Nationals rotation later this week, and therefore not lose a start to the sprained thumb he suffered last Thursday.