Zenner is expected to split backfield touches with Justin Forsett on Sunday against the Rams, according to ESPN's Adam Schefter.
The Lions are dealing with myriad injuries in their backfield, and while Zenner has been able to maintain his health, Forsett is the more experienced back. That being said, the latter was only signed earlier this week, which is why Zenner is still in play. Overall, a split backfield for a team that prefers to throw the ball doesn't lend itself to much fantasy success.