SANTA CLARA, Calif. (AP) The 49ers will be without safety Eric Reid for the remainder of the season after having surgery to repair a biceps injury Tuesday.
''Losing him is a big loss for our defense,'' defensive coordinator Jim O'Neil said. ''(Reid's) leadership ability, his versatility, his playmaking ability will leave us with an obvious void, but it'll be a great opportunity for some other guys to step up and fill those roles.''
Reid was one of San Francisco's most talented defenders. The 2013 first-round pick lines up at inside and outside linebacker, has covered tight ends and played both safety positions. He ranks second on the team with 62 tackles behind fellow safety Antoine Bethea (66).
Reid, a leader in the locker room, joins key defenders NaVorro Bowman (Achilles tear) and Arik Armstead (shoulder surgery) as out of the lineup while the defense ranks at the bottom of the NFL in both yardage and scoring.
''We're not getting a lot of get well soon cards from the rest of the teams in the NFL, but that's what this league's about,'' O'Neil said.
Second-year safety Jaquiski Tartt will be called on to replace Reid. It's a familiar scenario for the second-round pick from Samford, who replaced Bethea in the final eight games of 2015 after the veteran had a season-ending pectoral injury.
Tartt played well as a rookie in Bethea's place, making 34 tackles with a sack and an interception. He's played roughly 30 percent of the defensive snaps in 2016 and is ready to see an increase.
''He's got great range and ball skills. He's got a knack for reading the quarterback,'' O'Neil said. ''He's played a lot of football for us this year and he filled in and did a great job last year when Antoine Bethea went out. He's a good football player.''
The 49ers will try to avoid setting a franchise record with 10 consecutive losses Sunday when they travel to play the Dolphins, who have won five straight.
''To me, it doesn't feel like we're (1-9) right now,'' Tartt said. ''I feel like we've stuck with a lot of teams this year and the ball just bounced another way.''
Colin Kaepernick is looking to win his first start of the season after taking over for Blaine Gabbert.
''There is that feeling out there that we're not going to be in the playoffs, but we still have an opportunity to do some good things and build on for next year,'' Kaepernick said.
In his first two starts, Kaepernick completed just 46 percent of his passes. But in the three games since the bye, Kaepernick completed 58 percent with five touchdown passes and one interception for a passer rating of 96.9. He has rushed for a career-high 43.3 yards per game.
''You really try to be a well-rounded player,'' Kaepernick said. ''For me, that's something I try to stay focused on, being able to balance staying in the pocket, my ability to run and utilizing both of those when necessary.''
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