Christian Petersen / Getty Images Christian Petersen / Getty Images

The Nationals outrighted right-hander Cole Kimball to Class AAA Syracuse, taking the once-promising, now-rehabbing reliever off their 40-man roster. The Nationals now have 39 players on their 40-man roster, giving them space to make a possible addition. In order to be outrighted, Kimball first had to clear waivers.

Kimball, 27, remains stuck in a difficult rehab process that started with shoulder surgery in 2011. Kimball appeared in 12 games in 2011, flashing a high-90s fastball and a devastating split-finger fastball. But he developed a tear in his rotator cuff after he pitched three consecutive games for the first time in his career. Despite frequent signs of optimism, Kimball has yet to fully recovered.

This season, Kimball has appeared four games, two at Syracuse and two at the Gulf Coast League affiliate. The past two seasons, Kimball has pitched only 9 2/3 innings. His last appearance came June 27 for Syracuse.