It isn’t just Brock Purdy who will be under the microscope.

You may not have noticed, but there’s been a lot of focus on the quarterback position for the 49ers this offseason.

The questions surrounding Brock Purdy and the most talked about elbow ligament in the Bay Area have meant another offseason dominated by quarterback discussion.

Regardless of whether, as is gradually becoming the expectation, Purdy recovers from surgery to line up as the starter Week 1, or if Trey Lance or Sam Darnold is under center in Pittsburgh on opening day, it is indisputable the 49ers’ fortunes will hinge heavily on their success in finding consistent quarterback play.

Assuming he is ready to go when the 49ers face the Steelers on the road, Purdy will be under tremendous pressure to ascend further in his second year following a stunning rookie emergence.

If he isn’t, then the burden will either be on Lance or Darnold to fill the void and ensure Purdy’s absence does not cost the Niners.

Beyond the quarterback position, though, there are several players whose seasons will be under the microscope due to their importance to the 49ers’ fortunes.

Let’s take a break from quarterback talk (a strange request, I know) and look at the five 49ers under the most pressure for the 2023 season.

Christian McCaffrey

It’s difficult to overstate McCaffrey’s impact on the 49ers following his mid-season trade from the Panthers last year.

After joining the Niners, McCaffrey racked up 746 rushing yards and six touchdowns to go with 464 yards and four touchdowns receiving in just 10 starts. He reinvigorated a running game that was uninspiring with Elijah Mitchell on the sideline and transformed the passing game with his talents as a receiver.

McCaffrey became the ultimate safety net for 49ers quarterbacks as a check down option and gave San Francisco the ability to get to five wide formations from heavy personnel groupings. His passer rating when targeted for the 49ers was 116.9 (his season long mark was 106.8), trailing only George Kittle (127.2) among San Francisco pass catchers.

The dual influence of McCaffrey is best illustrated by the 49ers’ performance in Expected Points Added per play from the time of his first regular-season start to his last. During that time, the Niners were second in the NFL in EPA per play. In other words, the second-most efficient offense in the league.

There is little to suggest that cannot continue to be the case with all the weapons the 49ers have around McCaffrey. However, in terms of the arsenal, it is McCaffrey who is the most important, especially when it is not clear who will start the season at quarterback.

The uncertainty at quarterback makes the safety net McCaffrey provides even more pivotal. If the Niners are to thrive amid another potential carousel under center, they will need McCaffrey on the field.

Despite his well-documented problems with durability in his career, McCaffrey did not miss a game for the Niners following his arrival. It is imperative he once again stays injury free in 2023.

Colton McKivitz

Last year, the 49ers quietly rebuilt their offensive line extremely effectively. There were doubts about the ability of Aaron Banks and Spencer Burford to step in as starting guards, and questions around throwing Jake Brendel in at center having previously started just three games.

Though Burford split time with Daniel Brunskill – the interior line coalesced brilliantly – and the 49ers can head into 2022 with significant confidence in four of their starters up front.

The problem is that the O-Line can be defined by its weak link. It only takes one below-par player to send the best-laid pass protection plans of offensive coaches into disarray.

It is McKivitz who is the lead candidate to sink the 49er O-Line as he steps in for the departed Mike McGlinchey at right tackle. McKivitz will play next to Burford on the right side, the 49ers displaying evident confidence in the 2020 fifth-round pick despite him starting only five games in three seasons.

His performances in relief of an injured Trent Williams at left tackle in each of his last two starts – both wins over the Rams – underpin San Francisco’s belief in McKivitz.

But that is an extremely limited sample size on which to base their assessment of McKivitz. Coming off a season that ended with each of the top three quarterbacks injured, the 49ers can’t afford to have a clear weak link on the O-Line who risks putting their signal-callers in jeopardy in 2023.

Starting McKivitz is a bet by San Francisco that they can successfully develop him as they did Banks and Brendel. He must prove them right.

Drake Jackson

As I wrote in a recent deep dive on Jackson, there was plenty in his rookie season to leave the 49ers encouraged. However, he was kept out of the lineup down the stretch and in the postseason, his omission reason for concern about a defender on whom they are poised to rely heavily in 2023.

There is no real challenger to Jackson for the role of starting defensive end across from reigning Defensive Player of the Year Nick Bosa.

As such, the Niners really can’t afford for Jackson to fail to take a year-two leap.

He has taken steps to ensure that ascension does take place. Jackson has gone from 252 pounds to 265 in an effort to make sure he is better equipped to play more snaps and hold up more consistently against the run.

The challenge for Jackson will be to make sure he retains the explosiveness that is a key feature of his pass-rushing skill set even with the extra weight.

Succeed, and an edge defender with a well-refined approach to rushing the passer and exceptional athletic gifts could soon blossom into one of the 49ers’ best and most productive young defenders. A failure to rise to the challenge could leave the Niners searching for a solution to fill the void opposite Bosa and lead to scrutiny on their decision to draft Jackson.

The spotlight on Jackson will be intense as he makes the transition from rotational defender to likely starter.

Javon Hargrave

When you’re a 30-year-old player who receives as much money as Hargrave did from the Niners for his third NFL contract, you’re automatically under pressure to deliver.

San Francisco gave Hargrave $84 million over four years to revive an interior pass rush that was too often conspicuous by its absence in 2022.

Hargrave racked up 57 quarterback pressures, per Pro Football Focus, last season. San Francisco’s interior line finished with 75, with Arik Armstead the sole player among that group to even reach 20.

Thanks to the efforts of Bosa during his DPOY campaign, the Niners still boasted one of the most fearsome defensive fronts in the NFL. Yet to produce the kind of dominance up front that the Eagles enjoyed in the previous season, the 49ers need a consistent and destructive interior rush from Hargrave and Armstead to help take the onus off Bosa and Jackson.

Hargrave has established as one of the best interior pass rushers in football during an excellent career. The 49ers need him to quickly reaffirm that status to vindicate their free agency splash and put the defense in position to thrive early in Steve Wilks’ first season as coordinator.

Deommodore Lenoir

The 49ers secondary went from weakness to strength in 2022, in part thanks to breakout seasons from two players in the defensive backfield.

Charvarius Ward proved an extremely astute free agency signing, but the San Francisco pass defense would not have made such significant strides without the emergence of safety Talanoa Hufanga and corner Lenoir.

Hufanga earned All-Pro honors for his superb season. Lenoir’s efforts did not result in such praise, but were arguably just as important.

Following a season-ending injury to Emmanuel Moseley, Lenoir emerged as a versatile corner who can play inside-out, win with his impressive instincts in zone coverage and hold up on an island in man.

With Moseley gone, Ward and Lenoir are locked in as the two starting outside corners with Isaiah Oliver likely to play nickel.

The problem in the secondary is a familiar one, lack of depth. Ambry Thomas took a step back in 2022, Samuel Womack III played limited snaps as a rookie and the 49ers likely won’t want to rely heavily on fifth-round pick Darrell Luter Jr.

Losing either Ward or Lenoir to injury at any point would therefore be a significant blow to San Francisco. While the 49ers know they can have faith in Ward to reproduce his 2022 form, it is unclear whether Lenoir’s stellar second year was a one-off.

Thirteen starts of evidence from last year suggest the 49ers need not worry, but Lenoir quickly removing any lingering doubt with a fast start to 2023 would be a substantial boost for a defense hoping to remain among the elite.