San Francisco 49ers head coach Kyle Shanahan walked over to his quarterback, Jimmy Garoppolo, on the sideline and apologized. Garoppolo had just finished his third and last series of Monday night's preseason game against the Denver Broncos, and it was a disappointing and frustrating outing for the quarterback.

Shanahan wanted to keep Garoppolo in the game and get him more in-game reps but knew he would be risking his other starters' health if he had.

The 49ers won the game 24-15, but Garoppolo's outing has been described as "terrible" and "disastrous" by some media outlets. That may be a bit extreme (or maybe not), but it paints a picture of the overall thoughts on the quarterback's play against Denver.

No one is panicking, though. It was Garoppolo's first game in 11 months after a season-ending ACL injury last year. It was only natural that he might be rusty. That's what preseason is for, after all; to knock off any rust.

Garoppolo was 1-of-6 passing for no yards and an interception. You are reading that right. He had more interceptions than yards. It wasn't what Garoppolo, the 49ers, and their fans had hoped for in the much-hyped return for the 49ers signal-caller. The starting offense as a whole could not get anything going, and Shanahan finally had to pull his starting quarterback.

"It was frustrating for all of us because we knew we wanted to do something, but we know we're on limited time with it being the preseason," Shanahan told reporters after the game. "[We had to] get him out and wait a few more days until the next game. Luckily, we've got three games in 10 days so he'll get out there again."

The 49ers' next preseason game will be on Saturday against the Kansas City Chiefs at Arrowhead Stadium. Yes, the very same location where Garoppolo suffered his season-ending injury during Week 3 last year.

"It's something I haven't done in a year, obviously," Garoppolo said of his play against the Broncos. "I've got to knock the rust off and everything. Thankfully, we've got a short week this week so we can bounce back quickly. It's the first step of getting back into it."

Shanahan isn't discouraged by Garoppolo's play on Monday night. He already knows what kind of quarterback Garoppolo is. As Garoppolo said, it's just a matter of getting back in rhythm after missing so much time.

"I think everyone saw him the year (2017) that he played for us (and) the two and a half games that he had last year," Shanahan said. "I think everyone knows what we saw. It's just about getting him out there and getting him playing again."

Garoppolo's recovery from injury has been described as "flawless" multiple times by general manager John Lynch. Shanahan forgets that his quarterback is coming back from a knee injury. So does Garoppolo.

"I forget that his knee is hurt," Shanahan said. "The guy has been healthy since OTAs. We're not worried about the knee right now. We just want to get him out there and get some reps so he can play football. It was good for him because it's a big hurdle to get out there for the first time, but we haven't seen any issues with the knee.

"I would forget about it except that he's wearing a brace. I'm reminded there, but we're not too concerned about his injury. It's about him playing and getting reps with our team."

Garoppolo added, "Honestly, I really wasn't thinking about [my knee] out there, so I'm happy about that. Just, in general, it didn't bother me too much."

Garoppolo wanted the offense to get into more of a groove against the Broncos. That didn't happen while he was playing. The quarterback is eager to get to Saturday and see if it might happen in Kansas City.

"Obviously, as a competitor, you want to get back out there and put together a good drive, and string plays together, but that will have to wait until next week," Garoppolo added.