SANTA CLARA, Calif. (AP) San Francisco 49ers center Daniel Kilgore is scheduled to undergo season-ending surgery Tuesday on a fractured left ankle sustained in the third quarter of Sunday night's loss at Denver.
Coach Jim Harbaugh said Monday the injury is similar to what nose tackle Ian Williams suffered in Week 2 of the 2013 season at Seattle that required four operations and kept him sidelined until training camp this year. Kilgore, who will be placed on injured reserve, was carted off after getting hurt when linebacker Brandon Marshall inadvertently ran into his lower leg at the end of a run by Frank Gore during a 42-17 loss to the Broncos.
''It's similar. He was disappointed. He played well in the game. So that's an obstacle to overcome. He's made of the right stuff. No doubt that he'll overcome,'' Harbaugh said. ''He's been playing really well, better and better each week. Like I said, I thought he played really well in this game. Say a prayer and hope the surgery goes real well tomorrow, which I'm confident it will and we'll start healing.''
Marcus Martin, a 20-year-old rookie third-round draft pick, is the favorite to fill in for Kilgore on the starting offensive line. Martin recently returned to practice following a training camp knee injury.
Martin's NFL debut would likely be Nov. 2 at home against the Rams after the bye.
''We'll be moving forward and making that determination as we go,'' Harbaugh said, noting Martin has the upper hand.
Harbaugh said he would expect linebacker Patrick Willis, who missed Sunday's loss with a strained toe, and rookie cornerback Jimmie Ward (quadriceps) will return once the 49ers (4-3) are back from their week off. Players watched game film Monday, then were set to part ways for the week. Harbaugh said the 49ers would have Thursday through Sunday off from any work with coaches.
Replacing Kilgore is a big task.
''It's always tragic to lose a player,'' quarterback Colin Kaepernick said after the game.
While Martin hasn't played this season, he has ample experience at the position.
The 70th overall pick out of Southern California, he played 38 games - with 33 starts - over three seasons with the Trojans. Martin started all 13 games at center last year while helping USC rush for 2,419 yards and 29 touchdowns, and earning First-Team All-Pac-12 honors.
''He's exceled at the mental aspects- before and after he was injured. I've been real impressed with that,'' Harbaugh said. ''Even when 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. I think that bodes well. Bright youngster and he's champed at the bit to get back on the field and didn't take the opportunity to let the injury linger. So, good signs. Excited about his progress and I look forward to good things.''
Versatile offensive lineman Joe Loney also could take some snaps at center if needed.
A subdued Harbaugh hardly wanted to rehash the ugly defeat in Denver. He was pleased enough with special teams, but not much else went well.
''They outplayed us. Not going to go over every single specific phase of each of those two phases,'' he said. ''There's going to be some obvious, `Why didn't this? Why didn't that?' Right, didn't.''
Harbaugh himself planned to stick around and work, along with his staff.
''We have work to get done this week,'' he said. ''Preparation for upcoming opponents and self-scout and there will be players that will come in and we'll be available to those players.''
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