49ers’ Anthony Davis’ main position is tackle

On Thursday, head coach Chip Kelly said then-right guard Anthony Davis was "obviously" one of the team's best five offensive linemen and joked that he was sleeping better with Davis and tackle Trent Brown forming the right side of the line. Not only didn't he start at right guard in a 28-0 win over the Rams on Monday night, but Marcus Martin, not Davis, entered when starter Andrew Tiller missed two plays with a foot injury in the first half. A source has said Davis was absent for a "personal reason," and the San Jose Mercury News reported he was considering retirement after he left the NFL in 2015 to let his "brain and body" heal. Did Davis have misgivings about playing guard, a position he hadn't played since he was a freshman at Rutgers in 2007, before the 49ers asked him to make the move in August? On Monday, Kelly suggested Davis wasn't ready to handle his new role in a game that would include a matchup against All-Pro defensive tackle Aaron Donald. "We only have two (backup offensive linemen), so if both guards went down last night, he's going to have to go in at guard," Kelly said. Kelly said Garnett wasn't part of the 46-man roster because the 49ers had just two backup...