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For the first time since tearing his ACL at Arrowhead Stadium on September 23, Jimmy Garoppolo will take the field in something other than a practice setting. It likely won’t be for long, and we may not learn all that much, but the step is significant for a 49ers organization which committed its future to him after a five-game stretch in 2017. In addition to the other noteworthy upgrades the team has made, Monday will crucially provide a first in-game glimpse at the player who the 49ers will live and die by.

Here’s what to look for on Monday night, when the 49ers play the Denver Broncos in their second preseason game:

Jimmy Garoppolo

Monday night’s game will be all about the abbreviated performance of Garoppolo. There are plenty of questions about Garoppolo in what’s now his third season with the 49ers (and potentially his first full season). While he’s made excellent throws in practice, he’s also made egregious mistakes which have manifested in interceptions, something he’ll be expected to clean up come game time, a setting that generally plays to his abilities. Monday will show what strides he’s made in reading the defense at game speed.

The biggest step for Garoppolo, of course, will be getting hit for the first time. It shouldn’t be an issue, but it’s a necessary and important step to take now that he’s fully recovered from the torn ACL. Any contact and displays of mobility will surely be scrutinized to the enth degree, but the only real mobility-demanding play in which Garoppolo has struggled so far is a play-action pass rolling out to his left and throwing across his body.

It’s on those plays, in which he has to readjust his body to get the ball off, when he’s often underthrown passes or looked uncomfortable (in the general sense of the play, not physically). The issue has improved over camp, but it’s still a weak spot for him to shore up before the season starts.

The offensive line; will backups step up?

This is what the 49ers are working with on the offensive line. With Mike Person out due to a foot sprain, Najee Toran is the starting left guard. Assuming Toran and the starters play for their full set with Garoppolo and Toran goes with the starters (and potentially also with the backups for extra reps; the same may hold true for Ben Garland), the backup offensive line is Daniel Brunskill, Ross Reynolds, Wesley Johnson, Christian DiLauro and Justin Skule. Of that group, Skule is very likely to make the roster (along with Garland and Toran), leaving maybe one spot up for grabs.

#49ers' depth chart for Denver pic.twitter.com/aMhPA9DPKN

— Jake Hutchinson (@hutchdiesel) August 14, 2019

That backup offensive line had eight penalties in the first preseason game, and it may turn out to be who is least problematic in terms of securing the potential final spot (while the 49ers took nine offensive linemen last season, they could take eight to open up an additional defensive line spot, especially if they’re not enamored with their current depth options).

If the 49ers’ take just eight offensive lineman, that group is probably already set, barring injuries: Joe Staley, Laken Tomlinson, Weston Richburg, Mike Person, Mike McGlinchey, Skule, Toran, Garland.

Willie Beavers and DiLauro struggled mightily in Game 1 (Skule also had a penalty), so keep an eye out for someone like Ross Reynolds potentially taking the final backup spot, as well as Brunskill and the recently-signed Sam Young (following Shon Coleman’s injury) as a second backup tackle option.

The defensive line competition

Of the 49ers’ defensive line group, here’s who is pretty close to certain to make the roster: Dee Ford, DeForest Buckner, Arik Armstead, Nick Bosa, Solomon Thomas, Sheldon Day, Ronald Blair III. D.J. Jones is probably also in the group, but he’s dealing with a knee sprain and would be at the back end of that group if healthy. If the 49ers take nine defensive linemen, that leaves one spot. If the number is 10, there are two spots.

Of the remaining defensive line group, Jullian Taylor and Kentavius Street seem the most likely to take the final two spots, if those two spots are available. If it’s one, that spot probably goes to Taylor, although Street seems a hard prospect to give up on, considering his recovery from a torn ACL and the speed which he’s displayed in the rush over the last week or so.

It’s why 10 defensive linemen and eight offensive linemen is in play for this roster. Out of the remaining defensive linemen, Damontre Moore is probably a dark horse candidate to make the roster, as he’s looked better than Street for most of camp. It’s worth paying attention to the second and third defensive line units.

Tarvarius Moore, Ahkello Witherspoon and the secondary

This could be a night in which Tarvarius Moore secures his starting spot at free safety. That’s assuming it goes well, which, while a dangerous assumption to make for a second-year player still learning a safety position, is in tune with how well Moore has been playing. He’s demonstrated an ability to read the game better than was probably expected at this point, and he’s been inordinately active in creating turnovers; the bane of the 49ers’ 2018 existence.

How Moore and Ahkello Witherspoon (who, along with Richard Sherman, and most of the starters, didn’t play in Game 1) play could indicate where the 49ers’ secondary stands, and how much it has improved since last season. Moore and Witherspoon will both need to continue playing well to keep the starting roles they’ve thus far earned, with Jimmie Ward and Jason Verrett sure to be waiting in the wings come the start of the season to take their spots.

Also worth watching is the backup group of secondary players and the competition for the fourth safety spot and sixth corner spot.

The final safety spot (at strong, behind Jaquiski Tartt) is effectively up for grabs between Marcell Harris, Adrian Colbert and Antone Exum. Harris has looked the best by far out of that group and has made it appear like it’s his competition to lose. While Colbert’s a great in-box player, unless he shows a massive improvement in deep coverage, and immediately, he and Exum are likely the odd men out.

As far as the final corner spot, it seemed like Greg Mabin was in line to take it (as the fourth backup corner, third backup nickel). There was Sherman and Witherspoon at the starting corner spots (with Verrett third), then K’Waun Williams as the starting nickel with D.J. Reed behind him. Mabin looked like the plug-and-play depth option behind all of them. He was waived/injured (likely to injured reserve) with a serious calf injury which he sustained in practice on Wednesday.

With Mabin gone, it’s likely Emmanuel Moseley who takes the final corner spot. It does, however, open up the chance for sixth-round rookie Tim Harris Jr. to steal a roster spot, despite his underwhelming camp so far. It at least gives him a chance with a few preseason games to go.

The back end of the linebacker group

The 49ers finally have a reliable linebacker group. Led by Fred Warner, Kwon Alexander and the upstart Dre Greenlaw, there’s an unadulterated tenacity to the linebacking group of “Hot Boys,” as they aptly call themselves. Throughout the ranks, the linebackers have been extraordinarily active, and because of that, it’s actually one of the remaining competitions that’s genuinely unclear.

Aside from Warner, Alexander and Greenlaw, the only other safe(ish) bets are David Mayo and Elijah Lee, who consistently make tackles, but can sometimes be exploited in coverage. With six linebackers likely making the roster, it leaves one spot open for the following players: Malcolm Smith, Mark Nzeocha, LaRoy Reynolds, Azeez Al-Shaair, Demetrius Flannigan-Fowles.

Out of that group, only Flannigan-Fowles can safely be ruled out. It feels like Smith, who has woefully underperformed over the previous two seasons and has again struggled to stay healthy this training camp (hamstring tightness), is going to be cut. With so much youth available and the necessity for a modern linebacker to be quick, Smith’s time seems to have come and gone. Out of those remaining linebackers, Nzeocha has not done much to impress, while Reynolds and Al-Shaair have.

Reynolds looks like arguably the best coverage linebacker on the team, while Al-Shaair hits ball carriers like a wrecking ball and recovered a fumble in the first preseason game. They seem the most likely at this point to take the final spot, but as an undrafted rookie, Al-Shaair will have to continue to perform at a well above-average level if he’s going to be the sixth man. Keep your eyes peeled for those names in the second and third units (plus Alexander if he plays; though it seems like he might be held out until at least Kansas City).

The receivers

Who’s going to get reps with Garoppolo? Head coach Kyle Shanahan said he expected the two rookies in Deebo Samuel and Jalen Hurd, who have taken reps with Garoppolo in practice, will continue to get them with him in the game, but that’s not a guarantee, and depends on how Garoppolo’s drives go.

Aside from the rep watch and who, if anyone stands out, there’s still that competition for the final receiver spot between Kendrick Bourne, Richie James Jr. and Jordan Matthews.

Bourne was praised by Shanahan for having a “hell of a camp” and seems the favorite, but he continues to drop passes while James Jr., who’s also looked a solid punt return option, has been consistently good, and Matthews, while often lacking targets and making drops after running great routes, has made key catches in multiple successful Garoppolo practice drives. This competition, as always, is worth keeping an eye out for.

Bonus: Backup quarterbacks

This is a bonus section because the competition is Nick Mullens’ to lose. At this point, he simply is more reliable than C.J. Beathard, whose main praise-able attribute continues to be his toughness. Being a tough quarterback is great; Ben Roethlisberger is evidence of that. But Roethlisberger has also been fantastic at throwing the ball for most of his now 16-year career. Beathard has not.

It remains worth watching whether Beathard can swing the tide in his direction, and as a Shanahan-drafted guy, he’s got an additional edge. Shanahan has not shown he’s willing to give up on many of his draft picks thus far, and has consistently defended Beathard. There’s every chance, especially with Jerick McKinnon’s likely trip to injured reserve, that the 49ers’ take three quarterbacks rather than Shanahan’s preferred two, and maybe look for more time to secure a trade. But if there are just two quarterbacks on the roster, Mullens should be the second.