49ers' Kyle Shanahan talks Trey Lance, Brock Purdy, measuring QB growth

San Francisco 49ers head coach Kyle Shanahan plans to have third-year quarterback Trey Lance start Sunday's exhibition opener against the Las Vegas Raiders. Sam Darnold will likely get most of the second-half snaps. The extended playing time should allow both quarterbacks to prove how much they have progressed this offseason, assuming they can take advantage of the opportunity.

Lance and Darnold have been competing all offseason for the QB2 job behind starter Brock Purdy, who is returning from major offseason surgery on his throwing arm. All three have been under a microscope during training camp by the 49ers coaches and the media. After all, reporters are trying to predict what the final regular-season depth chart might look like.

How does the 49ers coach measure growth among his quarterbacks? He gave a detailed answer on Friday.

"You can just see how natural it becomes to guys the more they do it," Shanahan said on KNBR's "Tolbert & Copes" show. "Just getting in and out of the huddle, spinning the plays out. We've got some real wordy plays. Being able to spit that out, not going up to the line and having to think about [knowing the playbook]. Kind of that part of the game being automatic and just being able to adjust to the coverages and get the ball in the right spot."

Shanahan probably knows what he has in Darnold, a quarterback with 55 career NFL starts on his resume. Purdy and Lance have a combined 12 starts. What has their coach seen from each as far as growth is concerned?

"Trey has been tremendous this year, being in his third year doing it," Shanahan said. "And really, last year even, when he got hurt, just the way he approached it while he was hurt, never missing a meeting, being in everything. So he really got a lot of that stuff last year, just mentally, but didn't get it physically."

Lance entered last season as the starting quarterback but sustained a season-ending ankle injury during Week 2.

"And Brock being thrown into that fire last year, he was always studying, being ready to go, like everyone says, but holy cow, it happened to him pretty fast," Shanahan continued. "And he learned on the run and got prepared each week. And then he obviously had the injury. But going into this offseason, where he had to focus on getting healthy, but he could spend so much of his mental on what he learned in the seven games last year, and he really approached that the right way in the offseason.

"You can tell [since] he's gotten back here, he's been really detailed about some of the mistakes that he made last year, and he's trying to get it better right now."

You can listen to the entire conversation with Shanahan below.

Listen: Click here to listen on Omny.fm