SANTA CLARA, Calif. - 49ers coach Jim Harbaugh confirmed center Daniel Kilgore will undergo season-ending surgery on his ankle Tuesday after suffering a fracture in Sunday night's loss to the Broncos.
Rookie Marcus Martin, a third-round draft pick from USC, is the favorite to replace Kilgore in the starting lineup. Martin was viewed by many as the best center available in May's draft and was the final player selected that was invited to attend the draft and watch from the green room inside Radio City Music Hall.
Harbaugh said Kilgore's injury is similar to the ankle break sustained by defensive tackle Ian Williams in Week 2 of last season against the Seahawks. Williams required four surgeries, missed the entire offseason program and didn't return to the field until midway through training camp in August.
The 49ers are hoping Kilgore's recovery isn't as long or complicated as Williams', who had multiple surgeries to insert and remove pins in the ankle.
Martin suffered a left knee injury in Week 3 of the preseason and returned to practice in early October. Last week as the first time he practiced in full without being mentioned on the weekly injury report.
During his time off the field, the 20-year-old rookie impressed Harbaugh with his work in the classroom.
"He’s excelled at the mental aspects, before and after he was injured," Harbaugh said. "I’ve been real impressed with that...he knew he was hurt, knew he was going to be out multiple weeks. He did not ease off in terms of the classroom and the study. And that bodes well."
As young as Martin is, a player starting at his age isn't unprecedented on this 49ers offensive line. Right tackle Anthony Davis started five games before turning 21 during his rookie season in 2010 after being taken with the 11th-overall pick in the draft. Martin turns 21 Nov. 29
"Bright youngster. (Martin has) chomped at the bit to get back on the field and didn’t take the opportunity to let the injury linger," said Harbaugh. "So good signs and excited about his progress and looking forward to good things."
Reserve interior lineman Dillon Farrell replaced Kilgore after he went down with the injury and will be in the mix to start, as will Joe Looney, who played left guard in place of Mike Iupati Sunday. Looney shifted to center late in the game when Farrell temporarily exited after rolling an ankle.
E-mail Niners Digest: NinersDigest@gmail.com
Follow Editor-in-Chief Chris Biderman on Twitter.