Zac Stacy will start at running back for Rams, is a must-add on the fantasy waiver wire

Rams running back Zac Stacy will start versus the Jaguars on Sunday, according to NFL Netowrk's Ian Rapoport.

This will mark the rookie's first NFL start, which is a decision that comes on the heels of a disappointing running output from the Rams thus far. Stacy will replace Daryl Richardson atop the depth chart, who averaged a disappointing 2.7 yards over 42 carries during the team's first four games.

Fantasy Spin: Running back roulette is the game of choice for the Rams this season, and Stacy is the next landing spot. This decision could not have come at a worse time for Richardson's fantasy owners since the Jaguars have allowed over five yards per carry this season and nine runs of over 20 yards.

However, for teams in need of a running back, this is perfect timing. Stacy is still available in 90 percent of Yahoo! leagues, although risks remain. Stacy will have the starter's designation this week, but a committee approach with Richardson, Benny Cunningham and possibly Isaiah Pead could still be in the cards. However, if Stacy gets off to a hot start, that could squash that philosophy instantly. Stacy is a boom-or-bust flex option this week.