From Jack Stewart on Webzone:
Jake Brendel is the starter at center, and Brett Toth is projected to be his backup. Toth has been out with an injury for some time, though, and Drake Nugent (66) and Doug Kramer (58) have been snapping the ball. One of those two might be the primary backup in Week 1 of the regular season. Who starts against the Raiders might be telling.
Not many here have mocked Nugent or Kramer to the 53, but the post makes a valid case.
Similarly, for swing tackle:
Trent Williams and Colton McKivitz are the starting offensive tackles, but every team has to have a tackle who can play on both the right and left sides. Isaac Alarcón (67), Brandon Parker (60), and rookie Enrique Cruz Jr. (69) are competing for that spot. Though Vederian Lowe will likely assume that position when he returns from injury, it is not clear that he will be healthy by Week 1, and therefore, who would man the spot until he returns might be crucial.
Again: how many have mocked Parker to the 53? Stewart may have a point. With some injured players on the PUP or IR, surprising players may make the squad.