The Dodgers announced that right-hander Chad Billingsley has a partial tear of his right flexor tendon.
No timetable was announced for how long the injury will sideline him.
Ellis has been limited to 15 games this season because of the sprained ankle and a left knee injury that required surgery. He is hitting .170 with one RBI.
Ellis was in the starting lineup for Friday's game against Arizona.
Federowicz hit .131 with one homer and five RBIs in 18 games for the Dodgers.