Like most other NFL teams, if the Rams were to lose their starting QB for a significant stretch of games (i.e. 4+), they'd be in deep trouble. However, the Eagles have clearly shown that losing their starter (even one playing at an MVP level) isn't necessarily a death sentence. In case of emergency, Pederson was able to "break glass" on a veteran QB who not only had experience in the offense (from mini/training camp), but actually had playoff experience as well. And it clearly showed as Nick Foles was able to do a more than competent job of filling in for Wentz.
As the Rams are clearly in a Super Bowl frame of mind, I feel that they need to follow this model established by the Eagles and secure a competent backup. And no, I don't believe that Mannion is that guy (mostly from an experience standpoint).
It's unclear to me right now how many QB's the Rams are planning to keep on the roster next season, but I think that they should strongly consider placing a phone call to the newly-retired Carson Palmer (who has likely returned to SoCal) to see if he'd like to come on board as Goff's back-up and veteran mentor. And God forbid, should anything happen to Goff, Palmer (IMO) would be ready to step in without a lot of drop off.
Just a thought.
