Anthony Davis' recent shoulder surgery likely will keep the 49ers' right tackle out of most or all of the team's spring drills. The silver lining? It will give coaches a better opportunity to evaluate the intriguing mix of players vying to be the team's so-called "swing" tackle this season.
In recent years, the top backup at the position has been the starting right guard, Alex Boone. If there was an injury to either left tackle Joe Staley or Davis, Boone was tapped to fill in, meaning that someone else had to step into his guard spot and that two positions were disrupted. This year, the 49ers will look at newcomer Jonathan Martin as the possible backup tackle with former seventh-round draft pick Carter Bykowski and undrafted Luke Marquardt also in the running.
At 6-8, 315, Marquardt is perhaps the most physically impressive member of the offense (Lawrence Okoye gets the nod on defense), and he got plenty of buzz before last year's draft. But he was recovering from a foot injury last season and did not get drafted. He never was placed on the active roster by the 49ers.
Martin, meanwhile, started 23 games over the last two seasons in Miami and has played both right and left tackle. Jim Harbaugh last month said there was some interest in seeing if Martin could play guard where in 2015 the 49ers may be without starter Mike Iupati, who is entering the final year of his contract.
Davis, meanwhile, said he suffered tears to his labrum and bicep in Week 3 last year and played through the pain. He has not missed a start since being drafted in the first round in 2010.
"I recently had surgery for the first time ever," Davis wrote on Instagram. "Played the majority of the season with a (messed) up shoulder ... Never made excuses just got the job done. This game has a way of seeing what you're really made of. One of the reasons I love it. Next season I get to use both arms. lol it's on."
Last year both Staley (knee) and Iupati (shoulder) had minor offseason surgery and missed the spring sessions. The list of injured players in the 2013 offseason included defensive end Justin Smith (arm) and outside linebacker Aldon Smith (shoulder).
-- Matt Barrows