CSN Bay Area

The 49ers’ offensive line, considered one of the top units in the NFL for the past several years, did not hold up its end of the bargain last season.

The pass-blocking was not the sole reason quarterback Colin Kaepernick was sacked 52 times, but a lack of adequate protection was routinely an issue throughout the season. The run-blocking was also spotty, though the 49ers finished with a strong 4.6-yard average per rushing attempt.

The biggest dilemma facing the 49ers this offseason concerns three-time Pro Bowl left guard Mike Iupati. The 49ers prepared for the anticipated loss of Iupati via free agency with the selection of Brandon Thomas in last year’s draft.

But it’s obvious the 49ers need more depth along the offensive line. And it would not be a shock if the 49ers decided to bolster the line as early as the first round.

The top candidate for the 49ers, if they select an offensive lineman at No. 15, is Iowa’s Brandon Scherff, who checks in at 6 foot 4 5/8, 319 pounds. He played left tackle in college, but he would appear to be a prime candidate to move to left guard if he ends up with the 49ers.

“I feel like I can play guard and tackle—whatever they need,” Scherff said last week at the NFL Scouting Combine.

“I don’t think there would be a challenge. I like run blocking. It would be a little closer. You’re getting a little help from the center, also. I think it would it would be a smooth move for me. Like I said I’ll be happy to play wherever they want me to play.”

Here’s a look at the 49ers’ offensive line with free agency set to begin on March 10:

Left tackle: Joe Staley
Staley has started 64 consecutive games, so the 49ers’ depth at this spot has not been tested for long periods of time. On the 49ers’ depth chart last season, they did not even list a backup left tackle. And that's not a good thing.

Left guard: Brandon Thomas
Iupati could command a big payday on the open market. The 49ers might not want to exceed the $6.5 million annual mark they’re paying right tackle Anthony Davis. And some team is likely to go higher than that to lure Iupati. The 49ers selected Thomas in the third round last year, shortly after he sustained a clean ACL tear, to account for the possibility that he could be a starter this season. The 49ers can also include Joe Looney or the player who does not emerge as the starting center in the competition.

Center: Daniel Kilgore or Marcus Martin
Kilgore might have been the 49ers’ most consistent offensive lineman at the time his season came to an end with a fractured lower leg. Martin stepped in and started the final eight games. While he certainly did not grade out well, according to Pro Football Focus, the coaching staff had a much-higher opinion of Martin because he was on top of things mentally. This could shape up to be a good competition. Dillon Farrell, who made the team as an undrafted rookie, can play center and both guard spots, too.

Right guard: Alex Boone
Boone got off to a slow start after he skipped the team’s offseason program and all of training camp in a contract dispute. He ended the season strong, and should be in position to play much better from start to finish due to his expected attendance in the team’s offseason program.

Right tackle: Anthony Davis
The 49ers’ offensive line struggled last season. And the biggest reason was because of Davis’ inability to get on the field and stay on the field. He got a late start on rehabilitation from offseason shoulder surgery, then sustained hamstring, knee and concussion issues that limited him to just five full games. Jonathan Martin played most of the season, and his forte certainly is not the power-run game that the 49ers wanted to feature. Martin is scheduled to earn a little over $1 million, which places his status with the team in question. In addition to figuring out who starts at left guard and center, the 49ers need a reliable swing tackle.