Eldridge isn't a dynamic receiver, he's an old school blocking tight end. It's most likely a long shot for Eldridge to make the final 53, but he will have his chance.
If Eldridge makes the final 53, he will most likely fill the role that Billy Bajema left as the 3rd tight end, and will most likely be in the game as a blocker, or as a last option to catch a pass. Eldridge can also play fullback if the Rams need him to, so that could help him make the roster.
Besides Lance Kendrick, the tight end position should be wide open. The Rams will most likely carry three if not four tight ends.
Mike Hoomanawanui, is a returning tight end that should get the second tight end spot, but that position isn't guaranteed, he's injury history really doesn't help his case.
With nine tight ends on the roster, it's anyone guess who will make the roster, Sam Bradford needs help, so these players should help him, because a tight end is a quarterbacks best friend.