Jimmy Garoppolo’s game plummeted after sprained shoulder

Jimmy Garoppolo now has a right shoulder bum because he had a right thumb bum.

The 49ers quarterback suffered what head coach Kyle Shanahan called a “mild” shoulder sprain late in the second quarter of the 49ers’ 23-17 playoff win at Dallas.

About three minutes before halftime, Garoppolo was hit mid-run by defensive end Randy Gregory on an incomplete 3rd and 6th pass and fell on his outstretched right arm. Garoppolo landed awkwardly to avoid setting up his fall with his right hand and fractured thumb and he grimaced as right guard Daniel Brunskill helped him up.

“I went to reach out and kind of had in my mind that if my thumb hit, I didn’t know what was going to happen,” Garoppolo said. “So I tried to catch him a bit with my elbow and just stuck his shoulder.”

Does Garoppolo’s shoulder injury help explain his lackluster second-half performance? Shanahan said he didn’t think Garoppolo’s fall “had to do with his shoulder”, but suggested a reporter “could ask him”.

OKAY. Did your shoulder injury impact your performance, Jimmy?

“Being a quarterback affects every throw,” Garoppolo said. “So that definitely had an impact. But if I’m out there and put in that place, I still have to make the plays that I normally do. So no excuses or anything like that, but the wound is what it is.

Evidence suggests that Garoppolo’s aching right arm factored into his painful second-half stat line.

After his injury, Garoppolo failed to throw another pass in the first half after going 11 of 14 for 133 yards and making accurate infield throws that went 10, 11, 12 and 27 yards beyond. the line of scrimmage. An example: In the first quarter, 3rd and 10th from the 49ers 42-yard line, Garoppolo pulled back 10 yards and made a pass to the right sideline just before wide receiver Jauan Jennings made his pause.

The pass carried Jennings perfectly to the sideline for an 11-yard connection. First down. A thing of beauty.

The second half? It was ugly. Garoppolo completed 5 of 11 passes for 39 yards and none of his carries went 9 yards beyond the line of scrimmage (meters beyond the line of scrimmage on his carries: 6, minus-2, 9 , 5 and 4).

Meanwhile, Garoppolo’s six incompletenesses were a portrait of inaccuracy.

Biggest misses: He threw a runaway interception when he knocked down Trent Sherfield on a short throw and he missed a huge win when he air-slipped Brandon Aiyuk on a deep pass.

And there were also basements. Garoppolo appeared to short an elevated side pass to Sherfield which was kicked through the air and nearly caught by tense safety Jayron Kearse. And Garoppolo threw an injured duck screen at tight end George Kittle (a potential game-saving miss, given Kittle fumbled after pulling him off the turf).

Garoppolo’s other two incompletes were over-deep sidelines to Kyle Juszczyk and Jennings, although Juszczyk was well covered and it appears the throw to Jennings was a throwaway.

But, wait, there’s more.

Garoppolo nearly threw a second interception in the fourth quarter on a pass over midfield to Deebo Samuel who was cut off by cornerback Trevon Diggs and was nearly interrupted on the deflection (the game was called off by the 502nd Cowboys penalty).

“Every throw was impacted,” Garoppolo said. “It’s a shoulder injury, so any type of throw, you’re going to feel it. It will change things. So similar when I first dealt with thumb, my body is just learning and you have to adapt.

Garoppolo was asked which bothered him more, his shoulder or his thumb: “Yes”, he answered with a smile. “I don’t know. They’re pretty close.

Garoppolo’s most recent injury hasn’t had a significant impact on the 49ers’ run-to-pass ratio. Despite opening the second half with a 16-7 lead, Shanahan called for 19 points and 11 assists (first half: 19 points, 14 assists).

However, if Garoppolo starts the Divisional Playoff game against Green Bay on Saturday night, it will be fascinating to see the game plan Shanahan devises for a quarterback with a hobbled shoulder and thumb.

Does Garoppolo, who was restricted to practice on Tuesday, expect to play against the Packers?

“Yeah, we’ll feel it all week long,” Garoppolo said. “But, yes, I feel good right now.”

Other observations from the win over Dallas:

• There are so many small moments in games that have huge impacts on the outcome.

A prime example was a seemingly innocuous completion in a box score: “3-21-DAL 45: J. Garoppolo short pass from the right to K. Juszczyk at DAL 35 for 10 yards.”

No big deal, right? Wrong. Juszczyk’s supreme second effort on the 3rd and long catch that didn’t score a first down scored three runs. He appears to have been stopped by cornerback Anthony Brown at the 40 but ran through the tackle attempt and rushed forward for 5 yards more.

The result: Instead of throwing from the 40-yard line, Robbie Gould had the chance to score a field goal from 53 yards that gave the 49ers a 10-0 lead.

Without those three points, the 49ers could have led 20-17 in the final minutes, allowing the Cowboys to tie the game with a basket.

• Pass rusher Nick Bosa paid the price for making an equally huge, often overlooked play on the rush pass on which he suffered his concussion.

The situation: The Cowboys, after falling 13-0 down, had cut their deficit to six points, were aiming for a potential score with 1:19 to go before halftime and were close to receiving the kickoff of the second half.

On the 49ers’ first 39 down, however, Bosa’s power surge on La’el Collins lifted the right tackle off his feet and Collins attempted to recover by tackling Bosa from behind; Bosa was injured when his head slammed into DJ Jones’ leg. The Cowboys stalled after Collins’ holding penalty backed them from 10 yards and the 49ers were able to kick a field goal before halftime to take a 16-7 lead.

• Defensive end Jordan Willis, who was injured in the second quarter, played against what Shanahan revealed on Monday to be a sprained ankle.

And that’s a good thing for the 49ers that he did.

Willis, who played a bigger role (22 snaps, a season high) after Bosa left, got the game’s assist. On quarterback Dak Prescott’s pass in the third quarter that was intercepted by cornerback K’Waun Williams, Willis pushed the Pro Bowl to bull Tyron Smith deep in the backfield and slammed his left arm into Prescott’s chest in the middle of the throw, creating the errant pass.

The 49ers took a 23-7 lead on Samuel’s 26-yard TD run one play after the pick.

On the next practice, Willis did it again – intimidating Smith with a power rush – and Prescott was forced to rush for a 2-yard gain on a Cowboys 3-and-4 31.

The bad news for the 49ers: High ankle sprains usually sideline players for multiple games, meaning Willis is unlikely to be available to play against Green Bay. His loss, of course, would be minimized if Bosa approved the concussion protocol this week.

Eric Branch covers the 49ers for The San Francisco Chronicle. Email: [email protected]: @Eric_Branch