Trey Lance’s preseason debut was a rocky affair. He was sacked four times, nearly threw two interceptions, but finished with a 10-of-15, 112-yard, one-TD stat line that belied little of how it looked.

Kyle Shanahan addressed his performance on a conference call Monday, saying Lance improved over the course of the performance. He did say two of his four sacks could have been avoided:

I thought he played a lot better as it ended.

He came out, the first play was tough, the corner just keyed his three-step drop and sat on and did the right thing, he reset to go the tight end over the ball. But we had a bust. One of our eligibles busted on the play and put two guys in the same spot. So he had to protect the ball and take a sack there. Another sack on the 3rd-and-8 wasn’t his fault, we kind of had a jailbreak on it, but the two ones after that I thought he could have gotten rid of it a little bit before the sack and a couple of things he just hesitated on a hair early in the game.

But as it went, I think he made a huge third down on a 3rd-and-8, I think it was to Conley. Made a very decisive one in two minutes that got us down there to Troy [Fumagalli]. And ended up doing some good things.

What Shanahan appreciated most was the plays Lance cut loose.

Early in the game, you could see things moving too fast for the 23-year-old, like his internal clock was a second slow.

When he was decisive, he made a few plays happen. Even though his touchdown should probably have been intercepted, Shanahan pointed to that as a play he liked from Lance, encouraging him to play more aggressive:

I saw what he saw. The middle third safety cut the low cross and there’s a guy going behind him and what I like is he didn’t react and he saw a hole and tried to rip it. There was some guy coming from the backside that he didn’t see.

But it wasn’t a gun-shy throw. Those are things you learn from. I kind of like seeing him trying to make that play, regardless of the results, and obviously we got a little bit lucky and it ended up being a good result and I wouldn’t have been happy if it was a pick, but I can understand what he saw rolling out to the left.

Usually when that middle-third player cuts a route, someone’s vacated in the middle third and that corner was hesitant to get there, and so Trey didn’t see him and he let it rip. And those are the things I want to see more of. I mean, not picks and bad decisions, but play a little bit faster, a little bit more aggressive.

It’s hard to disagree with the assessment. Lance is in a tricky position where the 49ers can no longer wait around on his development, even though he’s fallen out of grace to little fault of his own.

In a competition with Sam Darnold, and to some extent, Brandon Allen, Lance has to show he’s capable of executing the offense to their level. Their decisiveness on Sunday was a step above his, which is understandable given the nearly year-long layoff Lance has had from game action. But Shanahan and the 49ers need results, which requires decisiveness at the quarterback position.