Manager Dave Martinez said after Sunday's win over the Giants that Finnegan is dealing with a cut on his finger, Mark Zuckerman of MASNSports.com reports.
Finnegan gave up a run on no hits and two walks in one-third of an inning Sunday, and Martinez believes the right-hander's laceration contributed to his struggles. The Nationals have a scheduled day off Monday, and it's not yet clear whether the 30-year-old will be available for Tuesday's series opener in Colorado.