49ers Notebook: Shanahan on Jimmy Garoppolo’s mistakes; D.J. Jones’ high praise for Arik Armstead; Deebo gets his wish

What did Kyle Shanahan think of Jimmy Garoppolo's performance against the Cowboys on Sunday? And what did D.J. Jones say after the 49ers' 23-17 win over the Cowboys that left Arik Armstead flattered?

Let's answer those questions and more in this roundup of notes and quotes from the 49ers' postgame press conferences.

* The good and not-so-good for Jimmy G: Quarterback Jimmy Garoppolo had an up-and-down performance against the Cowboys on Sunday, completing 16-of-25 passes for 172 yards with zero touchdowns and one interception. Garoppolo went 11-for-14 for 133 yards in the first half but cooled down considerably in the second half while having a couple moments that would have proven to be too costly had the Cowboys been able to successfully rally for the win.

One of those plays was an interception that gave the Cowboys the ball deep in 49ers' territory. The Cowboys soon scored to cut the 49ers' lead to 23-17, giving them momentum as the game headed into the final stretch. Another was a missed throw to a wide open Brandon Aiyuk that could have helped seal the game before the interception came about.

Garoppolo talked about each play with reporters after the win.

"The interception just got away from me—shot it high," Garoppolo said. "Then to BA, just another tough one. Those are the ones you've just got to hit. Those are the easy layup ones you've just got to make."

Shanahan's overall assessment of Garoppolo was similar to how it was described above—solid in the first half but not as much the rest of the way.

"I thought he played real good in the first half," Shanahan said. "I thought he made some real good plays in the second half too, but obviously that pick he'd like to have back and that one missed third down."

Shanahan had one other criticism of Garoppolo that wasn't as expected. He put the blame on Garoppolo for a failed fourth down quarterback sneak late in the game that was called back due to a false start penalty on left tackle Trent Williams.

"We just shifted to an unbalanced," Shanahan said. "It was on a silent count. It was quarterback sneak all the way, but Jimmy got real excited because of the look and didn't let Trent get set. He's got to let him get set. It ended up not being a problem though. I was going to struggle answering that though if we lost. But yeah, Jimmy's got to let him get set. Trent, it didn't look to me like he false started. He just didn't get in his stance yet."

Garoppolo seemed a little surprised at Shanahan's assessment.

"Kyle said that? Yeah, I mean, yeah, that's pretty much what happened," Garoppolo said.

* Arik Armstead, 49ers MVP? Defensive lineman Arik Armstead isn't a name that most would consider when deciding on the most important player on the 49ers roster, but defensive tackle D.J. Jones stated his case for Armstead on Sunday.

"He's the most important piece on this team, to me," Jones said. "I think Arik Armstead is a force. He can play outside, inside. He's a phenomenal three-technique. He can play 2i. He's a swiss army knife, and I love it when he's inside with me. That's my guy."

Armstead had four tackles, one sack, and three quarterback hits against the Cowboys and has given a big boost to the defensive line after moving inside to compensate for a season-ending injury to defensive tackle Javon Kinlaw. He returned the favor when informed about what Jones said about him earlier.

"That's high praise from D.J.," Armstead said. "I think very highly of him too. I think he's a big reason why we got this season turned around and the way he's been playing as well. I just try to do my part, help my team win games."

* That's my ball, punk: One of the biggest sequences of the game for the 49ers came in the second half, when an interception by cornerback K'Waun Williams led to Deebo Samuel scoring on a 26-yard touchdown run to give the 49ers a 23-7 lead. Not only did Samuel make a fantastic play on the touchdown, he also made sure Shanahan knew that giving him the ball would be a good decision.

"Right before he went out there, he mouthed something to me, which I kind of guessed—it was 'Give me the ball,'" Shanahan said. "When I look at him talking that way, it's extremely motivating and he makes it a lot easier to call plays."

Samuel described his encounter with Shanahan by saying, "I looked at Kyle and said, 'Hey, gimme the ball, I got you.' So I just went out there on the next play and scored."

The play wasn't expected to wind up in the end zone, but Samuel improvised a bit and made it work.

"It's not at all where we thought the play would go, where it's designed to go... usually it goes outside," Shanahan said. "He stopped, reversed the field, and if he gets a lane, he's running through everyone's arm tackles."

* Playing through pain: Garoppolo and Williams were on the field for the duration on Sunday after missing games due to injuries in recent weeks, but that doesn't mean they weren't still hurting a bit.

Garoppolo missed the 49ers' Week 17 win over the Houston Texans with a thumb injury, while Williams was sidelined for the playoff-clinching win over the Los Angeles Rams last week with an elbow injury. Garoppolo made it clear after the win over the Cowboys that he's still feeling some pain.

"It held up. Pretty much the same as last week. It's a day-to-day fight," Garoppolo said.

Williams was hurting as well, although he wasn't about to miss his opportunity to play in the postseason.

"No, I wouldn't worry about it. I felt it, but it wasn't nearly enough to take my mind off the game," Williams said.

Williams also gave some props to backup lineman Colton McKivitz, who stepped up in an unexpected start for Williams against the Rams.

"I thank Colton, because he played a great game last week and he gave us a chance to be here," Williams said. "I had to take advantage of it. I felt terrible not being there for my team last week, so I wasn't going to miss this game for anything."