I look at it like a Drew Brees/Chris Chandler situation.
Brees toiled for the Chargers after being drafted, but was about to be run out of town when they drafted Phillip Rivers in the 1st round. Rivers wasn’t ready to start right away and Brees had a very good last season in San Diego as he took the Chargers to the playoffs. His success led to a nice contract in New Orleans where he became a star and eventually won a championship.
Chandler parlayed 2 years of decent-to-good play for the Oilers (and Jeff Fisher) while they got Steve McNair ready into a nice contract from Atlanta. Chandler then helped lead the Falcons to the Super Bowl 2 years later and started for 5 years in Atlanta.
As long as the Rams don’t completely collapse this year, Case will probably start the entire year. If he does, there’s a good chance he gets a starting gig somewhere else next year. Too many teams that need QBs.