Cornerback Witherspoon out for season with knee injury

SANTA CLARA - One young cornerback’s season ended this past Sunday, and another young cornerback’s season just began.

The 49ers announced Monday they will place second-year starting cornerback Ahkello Witherspoon on the Injured Reserve List with a sprained PCL (posterior cruciate ligament) in his right knee. And they will replace Witherspoon in the starting lineup with rookie cornerback Tarvarius Moore, who will make his first career start this Sunday against the Chicago Bears.

Witherspoon’s knee injury will “take a few weeks” to heal, according to head coach Kyle Shanahan. But the 49ers’ season will end in 12 days, so Witherspoon won’t return in time to play. He will miss the rest of the season.

Witherspoon injured his knee this past Sunday during the first quarter of the 49ers’ 26-23 overtime victory against the Seattle Seahawks. Witherspoon was defending a run play. He chased Seahawks running back Chris Carson to the sideline, planted awkwardly on his right leg and collapsed.

For a few minutes, Witherspoon lay on the ground in agony. Seahawks quarterback Russell Wilson walked over to Witherspoon to check on him, and players from both the 49ers and Seahawks knelt on the grass out of respect for a potentially serious injury to a football comrade.

Luckily for Witherspoon, his injury isn’t serious.

Still, Shanahan sounded disappointed Monday.

“Wish he could’ve finished these last two games,” Shanahan said. “I think he definitely was finishing (the season) better than he started. His story is not written yet. He’s got to improve. Hopefully, he’ll come back here ready to go next year and take off the way he finished.”

Witherspoon, 23, was a third-round pick in 2017. He started nine games as a rookie last season, intercepted two passes and showed promise. The 49ers thought he was an ascending talent, so they handed him a starting job for 2018. Didn’t make him earn it or compete for it during training camp.

But, during the regular season, Witherspoon regressed and seemed to lose confidence. He intercepted zero passes, got benched once, committed 10 penalties (three were declined) and gave up six touchdown catches. To Witherspoon’s credit, he didn’t give up any touchdown catches the past four games, although he did commit four penalties.

“I thought he got a lot better in his coverage,” Shanahan said, referring to Witherspoon’s recent performances. “Just more consistent. Playing a little more physical in his coverage, too. I know he had some (pass-interference) calls over the last month, ones that I wouldn’t want him to play differently. I thought he did a real good job on all those. I liked how he got more aggressive throughout the year.”

Midway through the season, on Oct. 21, former 49ers safety and current television analyst for NBC Bay Area Donte Whitner called out Witherspoon on Instagram for playing passively and not tackling. “There’s no sense of urgency,” Whitner said of Witherspoon.

The past month, since Whitner gave his scathing critique, Witherspoon has played with much more urgency. Witherspoon seemed to get Whitner’s message. On Monday, Shanahan challenged Witherspoon to remember the message and carry over his competitive attitude to next season.

“Just come out the gate the way he finished,” Shanahan said. “Be aggressive with his hands at the line of scrimmage, be aggressive in his coverage and of course always do the same thing (against) the run.”

Next season, it’s no given Witherspoon will keep his starting job. He may have to compete for it with his replacement, Moore.

Moore, 22, is a former third-round pick like Witherspoon. The 49ers drafted Moore in 2018. He’s a rookie. He played safety at the University of Southern Mississippi, and has spent most of his rookie season with the 49ers learning to play cornerback.

When Moore replaced Witherspoon against the Seahawks, he gave up a touchdown catch to veteran wide receiver Doug Baldwin three plays later. But, Moore improved as the game went on, breaking up two passes and making seven tackles.

“I was excited to see him play,” Shanahan said, referring to Moore. “I know (the Seahawks) challenged him a number of times and he missed some plays, but I liked how he rebounded throughout the game. Similar to (wide receiver) Dante Pettis versus Tampa Bay. That was the first time we left him out there to play through things.

“That was the situation with Tarvarius (Sunday). Stuff that he struggled on earlier, I thought he did better in the fourth quarter. He plays physical. He doesn’t mind hitting. He showed that on special teams. He carried it over to the defense and looks like he had fun out there. Looked like it wasn’t too big for him.”

Let the competition begin.

Notable

Strong safety Jaquiski Tartt, who has missed the 49ers’ past two games with a shoulder stinger, still is suffering from the injury. “We’ll see on Wednesday whether he has a chance to go this week,” Shanahan said.

Tartt, 26, has missed six games this season. And he missed seven games in 2017. The past two weeks, rookie safety Marcell Harris has started in Tartt’s place and recorded 13 tackles.