Our starting center?

Did Shelton actually beat out Allen? Haven't read that this is a certainty. The big reason is I have heard that Noteboom or Ancurum will start at RG. Nobody is explaining Boom's supposed injury. Looks like Jackson beat him out at LT. McVay is touting Boom as one of his best 5 and his best 5 will start. Havs is safe at RT and Avila is indelibly written in at LG and yet, we still don't know for sure. Not much time left to sort it out and will the Rams keep Boom and Allen with their high salaries in the bench?
Logan Bruss was picked in the third round and called the steal by the Rams who said he was a starter at RG before he had a practice. He is now a backup tackle? And Ancurum last season who was an All American RT in college finally started at RG and got hurt early in that same game. Is he the answer at RG now? We've had many discussions about the OL and now, we still don't know.