If the Ravens actually do play Jackson, then it's because they feel that the outcome of this one game determines whether they play an 18th game or not.
Clearly Jackson is gimpy and an ankle injury like his can be aggravated and he can be set back. But on a strategic level, if you don't believe you can win without Jackson, and you believe that losing this game ends any hope of a playoff position, then perhaps you play him and cross your fingers.
The Rams are going to be in for a real battle for a team whose back is against the wall. Make or break. Do or die. But, that's football at this time of the year and I love it!