SAN FRANCISCO (CBS SF) — San Francisco 49ers head coach Kyle Shanahan said Monday that two penalties could have been called on the play that ultimately sidelined starting quarterback Jimmy Garoppolo in the team’s 31-13 victory over New York Jets.

Just four minutes into the game, Garoppolo was sacked by Jets defensive tackle Quinnen Williams who submarined the 49ers star below the knee. Then for good measure, Garoppolo was hit a second time while he was on the ground.

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Under league rules, a defender cannot initiate a roll or lunge and forcibly hit the passer in the knee area or below, even if he is being contacted by another player.

It’s generally nearly an automatic penalty. Not on Sunday.

“No it wasn’t (legal), they hit in right in the calf,” Shanahan said during his Monday news conference. “Right in the Achilles (tendon) so that was low. They didn’t call that and then they couldn’t blow the whistle because his (the referee’s COVID-19) mask was on. He couldn’t get the mask off in time. So while Jimmy is lying there and they can’t blow the whistle, a guy came and hit him again so I thought there should have been two penalties called.”

Garoppolo suffered a high ankle sprain on the play. He managed to hobble through the rest of the first half, throwing a pair of touchdown passes to Jordan Reed.

“Jimmy is a physical guy and a lot of guys it (getting an injury) gets them going in the game, gets them more into the game,” Shanahan said of Garoppolo’s improved play after the injury.

“Jimmy plays with a lot of grit, for him to hurt his ankle the way he did, the next series we had a third-down where people weren’t open — they got us in the right call — for him to scramble to the right when he barely could move and make that throw to (Brandon) Aiyuk to move the chains that led to a 14-play drive.”

“He really gutted it out. He’s as tough a guy as I have been around.”

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But Garoppolo simply could not go after halftime and was replaced by backup Nick Mullens. When asked about Garoppolo’s availability for Sunday’s contest against the New York Giants, Shanahan said the team will gauge his progress during the week.

“We’ll see how that goes this week,” he said. “He does still have a chance (to play) because the severity is not real bad but it is a high ankle (sprain).”

When asked a second time, Shanahan said Mullens will take some snaps this week with the first unit in practice to be ready to play if needed.

“Jimmy is our guy, if he’s good to go, the doctors say he’s healthy and he can go out and protect himself, if Jimmy feels confident… He gives us the best chance to win,” Shanahan said.

The rest of the injury list was not as hopeful. The team was still awaiting MRI results on Nick Bosa’s and Solomon Thomas’s knees, but both are more than likely out from Sunday’s game if not longer. It’s believed Bosa, the overall No. 2 pick in the 2019 draft, suffered a season-ending torn ACL. Running back Raheem Mostert will likely miss Sunday’s game with a diagnosed MCL sprain.

In addition, Shanahan said running back Tevin Coleman also suffered with a knee sprain, defensive lineman D.J. Jones sprained his ankle, and linebacker Dre Greenlaw had a thigh contusion.

To bolster the battered defensive line, the 49ers reached an one-year agreement on a one-year deal with veteran defensive end Ziggy Ansah.

The 31-year-old, seven-year NFL veteran played for 49ers defensive line coach Kris Kocurek while with the Detroit Lions. He appeared in 11 games last season with the Seattle Seahawks and registered 2.5 sacks with two forced fumbles and two fumble recoveries.

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“We agreed to terms with Ziggy,” Shanahan said. “Once he passes his COVID test it should be official. We hope to have him here by Wednesday. We played against Ziggy a ton. He’s a hell of a player who can rush the passer and play the run.”