SANTA CLARA — Late-morning practices, amid the South Bay’s gentle breeze, will greet the 49ers for their 20th straight training camp on their home fields.

They’ll be comforted by familiar surroundings, from their walnut-framed lockers to a protein-stocked cafeteria and other first-class amenities.

This camp, however, will come with a sense of unease.

For starters, a quarterback change is afoot, and nothing defines the 49ers’ power structure more than that position, as history reflects from last generation’s Lombardi Trophy collection.

This year’s supporting cast blends enough elite veterans with high-expectation upstarts to make a third playoff run in four seasons.

Here are the most intriguing storylines to follow as camp opens Tuesday with rookies and veterans reporting:

1. QB OR NOT QB

Trey Lance will tighten his grip on the starting quarterback job, barring an unforeseen comeback from Jimmy Garoppolo, who had shoulder surgery in March to delay a still-anticipated exodus.

How Lance adapts to the QB1 role, after being limited to essentially 2 ½ games as a rookie, will merit daily scrutiny, from trivial reports of his passing stats to amateur observations about his mechanics, body language and quotes.

Garoppolo’s rehabilitation stalled any potential trade, it excused him from June’s minicamp and it could mean he won’t be fully cleared to throw until mid-August, according to an NFL Network report this week; neither Garoppolo nor his agent has confirmed that timeline.

The stage is set for Lance to show why he was worth the No. 3 overall pick in last year’s draft.

He won’t be perfect. He’s just 22. He’s thrown just 71 passes in his NFL career, after just 318 at North Dakota State from 2018-20. And he just needs to lead a highly intricate offense back to the playoffs.

2. BATTLE IN TRENCHES

No position group packs more uncertainty about its starters than the offensive line.

Aside from All-Pro left tackle Trent Williams, the 49ers can’t be sure of what they have.

Is Aaron Banks, after just five snaps as a 2021 second-round draft pick, ready to replace Pro Bowl left guard Laken Tomlinson?

Is Jake Brendel the best option at center, even if Lance is in sync with him from their 2021 scout-team reps?

Is Daniel Brunskill entrenched at right guard, or can Jaylon Moore push him – or will Brunskill compete at center?

Is right tackle Mike McGlinchey, in the fifth and final year of his rookie deal, poised for a robust comeback from quadriceps surgery?

And, last but not least, are the homegrown backups enough competition after the 49ers ignored adding to the offensive line in free agency?

3. DEFENSIVE FRONT

All due respect to the importance of quarterback play in today’s NFL but these 49ers are most reliant on their defensive front, which, in today’s NFL, means an ability to pressure opposing quarterbacks.

Nick Bosa and Arik Armstead return as stalwarts on the defensive line. Gone are nose tackle D.J. Jones and Arden Key. Arriving with the top draft pick was Drake Jackson, whose burst as a defensive end will thrust him into a rotation with fellow edge rushers Samson Ebukam, Charles Omenihu, Kemoko Turay and Kerry Hyder Jr.

That unit’s secret weapon could be — must be – Javon Kinlaw, the 49ers’ top draft pick in 2020. He was highly encouraged this spring with how his surgically repaired knee was responding, and, if that optimism persists through the rigors of camp, then the 49ers’ front will be among the NFL’s best.

Bosa could get an extension before camp that reflects how he’s among the league’s best defenders, even if he’s yet to make All-Pro in his three seasons. The 49ers picked up his 2023 fifth-year option, so there’s not as much urgency as a potential Samuel deal.

4. DEEBO & CO.

Because the 49ers did not cave to Deebo Samuel’s trade request in April, a contract extension (projected: $25 million annually) should come any minute as camp approaches. A holdout is not expected, not at the risk of a $50,000 daily fine.

Samuel, after earning his first All-Pro honors last season, did not practice with the 49ers all spring. Neither did tight end George Kittle, for precautionary health reasons. That allowed Brandon Aiyuk and Jauan Jennings to enhance their obvious chemistry with Lance.

Add Ray-Ray McCloud’s experience in the slot and rookie Danny Gray’s speed on the outside, and the 49ers just might have their best receiving corps under Kyle Shanahan, albeit a relatively young one.

If there’s room for another wide receiver or an extra tight end, it will take an impressive training camp to prove that by … a player to be named later.

5. SECONDARY DEPTH

The 49ers are deeper at defensive back, or so it initially seems.

Ex-Chiefs starter Charvarius Ward definitely upgrades the cornerback group. Emmanuel Moseley and Ambry Thomas figure to jockey for the other starting spot, though Moseley could also slide into the slot as the nickel back, where rookie Sam Womack is contending with Darqueze Dennard and Deommodore Lenoir.

Spring workouts cast Talanoa Hufanga as Jaquiski Tartt’s replacement at strong safety alongside the perennially underrated Jimmie Ward. Hufanga is a hustling, passionate ball magnet. But he will have to win that job outright, and among his challengers are Tarvarius Moore, George Odum and undrafted rookies Leon O’Neal and Tayler Hawkins.

Source: www.mercurynews.com