SANTA CLARA -- When the 49ers began their final minicamp practice last week, long-time right guard Alex Boone was playing left guard with the first-team offensive line. The line looked like this:
LT Joe Staley
C Joe Looney
RG Marcus Martin
RT Erik Pears
Boone didn't stay there throughout the session. He played left guard with the second-team offensive line at times and Andrew Tiller, who had filled in at guard for most of the offseason when Boone was absent, was back with the first-team unit.
At center, Daniel Kilgore (ankle) is expected back during training camp and, barring medical complications, likely will retain his starting spot. Still, the above group probably offers a good glimpse of what a rebuilt 49ers offensive line will look like in mid September.
There could be more tinkering, or what offensive coordinator Geep Chryst termed "probing," to find the right combinations of players. But it stands to reason that the coaching staff wants to provide a maximum amount of time for the new line to congeal and get used to playing with one anther. After all, only one player -- Staley -- is in the same position he was in at the end of the 2014 season.
One of the things the offensive coaches asked during the spring practices was, 'Who has the athleticism for the up-tempo style the team hopes to use in 2015?'
"We feel great. Now can we feel good in October and November?" Chryst said. "But we feel great right now and the next step right now is to put the pads on and find out if we can keep that. Because the collisions will be a little more violent and the frustrations will bubble up. But I really believe that we set a real nice fundamental framework that we can start to fill in."
One question is why the 49ers would move Boone from the right side, where he has started since the 2012 season, to the left. For his part, Boone noted he was primarily a left tackle through college and is familiar with the footwork on the left side. Of his 35 starts at Ohio State, 22 of them came at left tackle. He also served as a tackle during his first three seasons with the 49ers.
Chryst, meanwhile, said the move gives the 49ers a better fallback if their best lineman, Staley, goes down with an injury.
"When you lose a guy of the caliber of Joe Staley, what's your answer?" Chryst asked. "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."
"Again, it's the whole idea of probing (for) the best (combination)," he continued. "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. And I think he's been doing a really nice job over there. And we can protect Joe and protect our position because it's as easy as moving over one (spot)."
What about Evan Mathis, the talented left guard the Eagles released last week? Mathis, 33, seems to be taking his time in figuring out the best landing spot. But you would have to imagine the 49ers, who now have plenty of salary cap space, have at least considered Mathis.
Mathis’ agent, Drew Rosenhaus, said at least “half a dozen” teams have inquired about his client. "Between now and the start of training camp I definitely expect him to have a new home,” Rosenhaus told WQAM radio last week. “I think we'll be methodical. We won't necessarily rush into signing immediately. Clearly Evan is one of, if not the, top overall free agent right now that would be available in the NFL."
The 49ers may conclude that, after losing long-time starters Mike Iupati and Anthony Davis this offseason, they could stand to add a veteran like Mathis. Or they could decide that they have an abundance of young interior offensive lineman who need seasoning and that bidding for an 11-year veteran who had been slated to earn $5.5 million this season is not a wise investment.