49ers training camp : It’s not Brock-or-bust at QB for Shanahan & Co.

The biggest question entering 49ers enter camp is which starting quarterback will emerge, whether it's a healthy Brock Purdy, a revitalized Trey Lance or a newcomer in Sam Darnold.

SANTA CLARA – Listen carefully to anyone who tells you which 49ers quarterback will start this season. Then ask them for the lottery numbers while they’re at it.

No one definitively knows anything.

Brock Purdy’s return date from a surgically repaired elbow won’t be clear for several weeks, at least. His six-month recovery timeline coincides with the regular-season opener at Pittsburgh (Sept. 10), so the 49ers have time to proceed with every option available.

Unlike in the NFC Championship Game loss at Philadelphia, they have appealing options behind him.

Four quarterbacks enter camp on the roster: Purdy, Trey Lance, Sam Darnold and Brandon Allen.

Three quarterbacks are eligible to suit up on game days, courtesy of the NFL’s Purdy-inspired bylaw that passed this offseason.

Lance and Darnold, who presided over the offseason snaps, will battle it out in camp for the starting role if Purdy isn’t ready. If Purdy is cleared for Week 1, then the Lance-Darnold “competition” is for the QB2 backup role, with no guarantee of a QB3 job.

Just when you thought a 49ers training camp couldn’t offer a more bizarre spectacle than Jimmy Garoppolo throwing on a side field last year, that scene could be topped this summer.

Welcome to the 49ers’ quarterback dragnet. Here is what to expect from the foursome:

BROCK PURDY

As long as his right arm continues to cooperate in rehabilitation, Purdy could be the one throwing on the side this year, a la Garoppolo last year.

It’ll be interesting to see if the 49ers place him on the “physically unable to perform” list to open camp, which would allow them to keep him on it for the first six weeks of the season if he needs further recovery time. Purdy could come off PUP before the season, or he could avoid the list altogether, which would be the ideal scenario, allowing him to interact with teammates on the practice field.

It’s not as if the 49ers are fast-tracking Purdy’s comeback. His March 10 surgery afforded him a quicker timeline when an internal brace procedure was used to repair a torn ulnar collateral ligament, rather than Tommy John surgery, a reconstruction that would have kept him out a year.

Purdy began throwing footballs in June as the 49ers wound down their offseason program, then he headed to Jacksonville to throw like he did last year with private tutors Will Hewlett and Tom Gormely.

TREY LANCE

Odds are you’ve heard outsiders or national reporters speculate that Lance will be the odd man out, simply because they haven’t seen him play much in two years (while Darnold has played).

Sorry, but Lance is their most prepared asset, and he should be the frontrunner ahead of Darnold, who does have time to rally.

That isn’t so much about the 49ers wanting to get the most out of their 2021 draft investment in Lance by reviving his stock. He genuinely appears to be as much of a QB1 as he did last year, when he served in that role through the offseason, training camp and the start of the regular season until his right ankle crumpled in Week 2.

Assuming Lance avoids further injury (2022 finger/knee; 2023 ankle), he must use camp to prove more accurate with his passes. Lance, with his positive attitude and work ethic, has his teammates’ widespread support.

SAM DARNOLD

Learning and adapting to a new offense has been an annual challenge in Darnold’s NFL existence. Is four months enough time for Darnold to master Kyle Shanahan’s complex offense?

Darnold’s time with the New York Jets (2018-20) and Carolina Panthers (2021-22) saw him play for four coaches and five offensive coordinators. The 49ers feel they’re offering a stable environment to maximize his obvious talent as a polished passer.

Darnold already has great rapport with two of the offense’s catalysts – Christian McCaffrey and George Kittle – so establishing chemistry with others is key in camp, but not as big a priority as nailing the details and timing required in this offense.

BRANDON ALLEN

Look at Allen as a wild card in this quarterback chaos. Shanahan was “extremely impressed” by him in offseason workouts after Allen signed in free agency, leaving behind his backup role with the AFC-contending Cincinnati Bengals.

“He is obviously not just a camp arm around this league,” Shanahan said in June. “He’s been a backup for a while, but just how good he’s done in his OTAs and stuff is going to give him a chance with us.”

If Purdy’s comeback stalls, or if Lance becomes a trade target for a team that loses its starter to injury, or if Darnold doesn’t pan out in his 49ers arrival, then Allen could be in play for a roster spot. Bringing him back to the practice squad – for potential emergency QB duty on game days – would seem like a longshot in a league that will have others courting his experience.