Kelley and Compton both were injured in Sunday’s loss to the Vikings. Kelley aggravated a high ankle sprain and sprained his MCL, while Compton was lost to a season-ending Lisfranc sprain in his foot.
Reid, 25, arrives in Washington after spending time with the Lions and Chargers during his four-year career. He has appeared in 34 games, making 36 tackles and three sacks.
Marshall joins Samaje Perine and Chris Thompson in Washington’s running backs room. He appeared in three regular-season games with the Eagles last season, getting 19 carries for 64 yards and three catches for 10 yards.
Washington also announced it released defensive lineman Tavaris Barnes from the practice squad.