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The Indianapolis Colts don't play until Monday night, but Marlon Mack is definitely worth a speculative add if he's still available. The electric rookie has been a catalyst for the Indianapolis offense every time he takes the field, rushing for 91 yards and a touchdown on just nine carries in Week 5.

Mack is a dangerous pass-catching weapon out of the backfield and he's also capable of hitting the home run in the running game, although his running style is certainly boom or bust. It's worth noting that he's still mired behind Frank Gore, who has been in the NFL for almost forever.

However, Mack is one of those high-upside stashes that could be a potential league-winner if Gore suffered an injury. He could also develop into a flex-worthy option -- similar to Tevin Coleman -- even as the lesser-utilized part of a committee.