"(If) you lose a guy of the caliber of Joe Staley, what's your answer?" Chryst asked a group of reporters. "By getting Alex repped on the left side, it's more natural to move him from left guard to left tackle than, hey, he's a right guard, right tackle and you flip him over to the left side."

Boone has plenty of experience on the left side of the field. In college, the 6-foot-8, 300-pound lineman made 22 of his 35 starts at Ohio State as a left tackle. In the NFL, however, Boone has primarily played as a guard except for a 2013 regular-season matchup in which he stepped in for an injured Staley and held St. Louis Rams star pass-rusher Robert Quinn to zero sacks in a home victory.

Boone's whereabouts on the offensive line will be an intriguing storyline when training camp begins in less than two months. The veteran lineman gives the 49ers coaching staff options in that he seemingly has the ability to play four spots..

"I think it's a great opportunity for us, at this time, to put him on the left side and see how natural he feels," Chryst said. "And I think he's been doing a really nice job over there."

Jim Tomsula explained the Boone scenario as one that would give San Francisco added line depth.