I'm gonna go with Brian Quick. Both have really great matchups, but the STL/PHI game should be higher scoring.
Royal's targets are interesting. Dude doesn't have a single catch in 2 WR sets. He's only making an impact when SD goes 3 wide.
Royal has a better chance to score, but Quick should see more targets and receptions. STL is sticking with Davis at QB as well, and he seems to like Quick