The only thing that seems certain for the 49ers secondary Sunday is strong safety Jaquiski Tartt will return from a two-game injury absence.
Otherwise, just about everything is up in the air.
Veteran cornerback Richard Sherman returned to the practice field Thursday, three days after Kyle Shanahan said he “probably expects” Sherman to sit out again due to a recent calf injury.
Cornerbacks Greg Mabin, Jimmie Ward and Ahkello Witherspoon all rotated among the two top spots against the Chargers with Sherman sidelined, which could continue Sunday against the Cardinals, while the team tries to figure out the best mix on the outside. Sherman’s return would mean those three would only be rotating at the cornerback role on the right side, with Sherman occupying the left.
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“(I’m) really looking for one of them to grab hold of it and have a stranglehold on it and not let it go,” defensive coordinator Robert Saleh said. “When you get your opportunities in this league, never leave doubt. That’s all the way across the board. ... It’s a challenge to the entire defense to grab your job by the neck and choke it out.”
The player who strangled his responsibilities best in the last game was Mabin, who entered in the second half and allowed just two catches on five targets, according to Pro Football Focus, and was credited with four tackles and a forced fumble.
“I’d consider that a very fruitful day for (Mabin),” Sherman said. “I thought he went out there and executed. He played hard. He brought energy, intensity, we were happy about it. The coaches have been talking about him for weeks because he’s had amazing days in practice, he’s been incredibly locked in and executing so it was good to see him get his opportunity.”
Mabin was a rare bright spot at cornerback for the 49ers this season, who have struggled opposite Sherman. The team’s 11 passing touchdowns allowed through four games this season is tied for the third most in the NFL. Sherman has allowed just one reception in six targets with his new team, according to PFF. Ward and Witherspoon combined have allowed 24 catches on 38 attempts.
Both Shanahan and Saleh have raved about Mabin’s play during recent practices while he’s stood in the shadows behind more notable players like Ward and Witherspoon, who are former first- and third-round draft picks, respectively.
“My mindset was just to play, learn my role and just play that role to the best of my ability,” Mabin said. “Whether that was scout team, practice squad, special teams, even as a starter.”
The 49ers are Mabin’s third team after getting released by the Buffalo Bills, who signed him after getting released by Tampa Bay. He joined the Bucs as rookie free agent following a college career at Iowa, where he was teammates with quarterback C.J. Beathard and tight end George Kittle.
Mabin late in 2017 replaced Dontae Johnson in a game against the Chicago Bears and later against the Houston Texans. But a calf injury during practice prevented him from building on his new-found role. He felt fortunate the coaching staff thought enough of him to bring him back this offseason, despite the team drafting defensive backs Tarvarius Moore and D.J. Reed.
“At one point, I wasn’t sure if I was going to get that chance ever again,” Mabin said. “But the coaches kept their faith in me. They brought me back, made the team during camp and everything and I’ve just been continuing to grind.”
Then there’s the question at free safety. Shanahan said he expects Adrian Colbert to work back into the starting lineup “eventually” after Reed was given his first career start against the Chargers. Colbert has been a full participant in practice the past two days. He was available to play Sunday, but Shanahan went with Reed at safety because he was the healthier option.
“We believe he’s going to be much healthier this week, so I’d be surprised if he wasn’t out there,” Shanahan said of Colbert.
Staley sits, but others return — Pro Bowl left tackle Joe Staley missed his second straight practice on Thursday after suffering a knee injury in the second quarter of the loss in L.A. His status for Sunday appears up in the air, though he worked out during practice without a brace, which seems promising.
Staley last missed a game in November after breaking an orbital bone surrounding his right eye against the Eagles. Garry Gilliam would likely be his replacement if he can’t play.
Center Weston Richburg and rookie first-round pick Mike McGlinchey returned to the practice field after missing Wednesday’s session. McGlinchey said he had an MRI on his knee that came back clean and indicated he’s expecting to play. McGlinchey hadn’t missed a practice during a game week since middle school, he said.
“I feel pretty good,” he said. “I should be okay.”
Receiver Marquise Goodwin (hamstring, quadriceps) also returned to practice after getting an extended warmup on the side field. He was listed as limited.