SANTA CLARA, Calif. -- In the days after the San Francisco 49ers' last-second loss to the Green Bay Packers, the public drumbeat for rookie quarterback Trey Lance to be more involved in the offense has gotten louder.

But Niners coach Kyle Shanahan made it clear on Wednesday that Lance still isn't pushing Jimmy Garoppolo for the starting job and that Lance will be sprinkled into the offense when he believes it makes sense.

"There's not a quarterback battle right now," Shanahan said. "We're going with our starting quarterback who I think is playing very well. I'm happy that he is, so Trey is not thrown into any situations he has to do too early. If he ever is thrown into that, then I know Trey will deal with that and he'll get better as it goes, but we have a luxury where we don't have to do that yet to Trey or to our team."

The questions about getting Lance more involved came on the heels of another uneven offensive performance for the 49ers in their 30-28 loss to the Packers on Sunday. For the second week in a row, the offense didn't score any points until just before halftime and those came on a 1-yard run by Lance as time expired in the second quarter.

Before those scoring drives against Philadelphia and Green Bay in Weeks 2 and 3, the 49ers' offense gained an average of just 65.5 first-half yards and 7 points in the first half of those games.

Those slow starts, combined with the Niners' recent spate of running back injuries -- Raheem Mostert is out for the season with a knee injury, JaMycal Hasty is on injured reserve with a high left ankle sprain and Elijah Mitchell didn't play last week because of a right shoulder injury -- left some to wonder if Shanahan might turn to Lance more frequently to help ignite a sagging run game or, at minimum, give the defense something different to look at.

"If we thought that would be the case, we'd do it," Shanahan said.

Asked Wednesday what he'd need to see from Lance in practice in order to get him more involved in the offense, Shanahan again reiterated what Lance's current role is.

"Trey's our backup quarterback," Shanahan said. "This isn't the preseason. We're not just going back and forth all the time."

Through three games, Lance has played just seven snaps, accounting for two touchdowns in those limited opportunities. He did not play against the Eagles in Week 2. While the 49ers have specific packages and plays in for Lance, he said he doesn't know when he's going into the game, which is why he stays close to quarterbacks coach Rich Scangarello awaiting instruction.

"There's no certain situations that I know that I'm going in or don't just stay ready just like all the other tight ends and receivers and running backs that are subbing out of the game," Lance said.

Garoppolo, meanwhile, has had his ups and downs for the 2-1 Niners. Despite the slow starts, he ranks 13th in the NFL in total QBR (56.9), 19th in passing yards (760) and tied for 18th in touchdown passes (four). He also has run for a score, thrown an interception and lost a pair of fumbles.

Which has apparently been enough for Shanahan to not only continue with Garoppolo as the starter but also limit how many snaps Lance is getting. It's also why Shanahan seemed to take umbrage with some of the chatter about how the quarterback situation would play out before this week and the ensuing questions about why Lance hasn't appeared with much frequency.

"We have put him [Lance] on the field," Shanahan said. "We do it in situations. You can go with whatever you want what I say in training camp and you can expand on that or not. But I think I was asked coming off the field of our third [preseason] game if we'd see this in the regular season, I said, 'probably not.' So, I think a lot of words have been put in my mouth with some of that stuff or exaggerated pretty big. So, I pretty much keep it pretty real to everyone, but I don't just tell everyone the answer.

"But I've been pretty consistent with what I've said."