If he doesn't know the routes cold, he won't play IMHO. Plus the blocks. Assignment driven. Maybe he won't learn every player's responsibility on O (like Stafford/Kupp) but he HAS to learn his assignment on any play that McVay calls.
There's a reason why the first pass he saw from Wolford wasn't until the 2nd preseason game. Skow and Tutu know the route trees, so they will play before Lance. And it's not trivial, learning every route in McVay's playbook.
But once he gets it (and it could take all year), I see him as potentially replacing Van Jefferson as our #3, as a starter. Certainly in the mix competing with Skow especially.
RFS69