Larsen went down Week 17 against the Kansas City Chiefs with a knee injury. The Broncos don't have a true fullback on the roster to replace him.
Denver replaced Goodwin on the practice squad with wide receiver Tim Toone who spent 2011 on the Buffalo Bills practice squad and 2010 on the Detroit Lions practice squad after being drafted by them in the seventh round.
Full press release after the click:
"The Denver Broncos on Tuesday signed wide receiver D’Andre Goodwin to their active roster and placed fullback Spencer Larsen on injured reserve.
Also on Tuesday, Denver signed wide receiver Tim Toone to its practice squad. Goodwin (5-foot-11, 188 pounds) is a rookie who spent the majority of the 2011 season on Denver’s practice squad after signing with the Broncos as a college free agent from the University of Washington.
Toone (5-foot-10, 185 pounds) is a first-year player who spent time on practice squads with Buffalo (2011) and Detroit (2010) after being selected by the Lions in the seventh round (255th overall) of the 2010 NFL Draft from Weber State University."