1. QB Blaine Gabbert. No. 2
Jim Harbaugh on Friday rejected the notion (that he created) of any murkiness at the backup position and threw support behind Gabbert. Ah, but Harbaugh has done that before with struggling players -- A.J. Jenkins springs to mind -- in an effort to boost their confidence and snap them out of their funk. Gabbert will be the second 49ers quarterback to enter the game and needs a far stronger showing than his 3-11 effort against the Ravens in the preseason opener. Gabbert drew a smattering of boos at Friday's open practice at Levi's Stadium. Another poor performance and they are sure to grow louder.
2. LB Chris Borland. No. 50
He's likely to start his second straight game but only because the 49ers are being cautious with Patrick Willis. Losing NaVorro Bowman is awful. Losing Bowman and Willis? Disaster. The undersized Borland is fun to watch because he darts about the field like a hyperactive terrier. Coaches want to see him hone that enthusiasm over the last three warm-up games.
3. G Joe Looney. No. 78
He didn't get high marks in the preseason opener in Baltimore because, well, he played too high and got off balance. Looney seemed to remedy that issue during the ensuing three days of practice against the Ravens' stubby defensive linemen. It will be interesting to see if he can put what he learned to practice against the Broncos. Meanwhile, Alex Boone's training-camp holdout is at 25 days and counting.
4. Jimmie Ward. No. 25
No team attempted as many passes last season as the Broncos, which means the 49ers' nickel defense ought to get plenty of work. As a result, fans ought to see a lot of the 49ers' first-round draft pick, Ward, who has had a strong training camp. Opportunities in which Ward is matched against veteran receiver Wes Welker promise to be an excellent learning experience for the rookie.
5. NT Ian Williams. No. 93
If the game resembles the recent practices, Williams will get a smattering of snaps, including any along the goal line. He's been seemingly unaffected by the leg fracture that sidelined him for so long. Still, there's been little game-like physical contact in practices and the Broncos' offensive line ought to offer the push he needs to truly gauge his readiness.
6. QB Josh Johnson. No. 1
He outplayed Gabbert in the preseason opener and seemingly has an opportunity to convince Harbaugh that the 49ers are better off with him, not Gabbert, behind Colin Kaepernick this season. Johnson has the smoothest throwing motion of all the team's passers, has a strong arm and can pick up yards with his feet. He needs to make a statement in preseason games two and three that Harbaugh and the front office can't ignore.
7. WR Brandon Lloyd. No. 84
From the start of the offseason program until now, perhaps no 49ers receiver has been as consistently good as Lloyd. Still, given his age, 33, his one-year contract and the fact that he doesn't play special teams, the veteran receiver is very much on the 49ers' roster bubble. A strong showing in the preseason, especially with Kaepernick throwing him the ball, could nudge Lloyd onto the roster.
8. OT Jonathan Martin. No. 71
He would have had a good game against the Ravens had he not tripped while pulling out on a run play near the goal line and had he not been guilty of a false start. Martin will be matched up against Broncos defensive end Derek Wolfe, who at 6-5, 285 pounds is the type of powerful rusher Martin has struggled against at times during training camp.
9. CB Kenneth Acker. No. 38
The sixth-round pick has come on a bit in recent practices, including a two-interception performance in a recent session. The 49ers could be eying Acker for the practice squad this year. Of course, they had the same intentions last year for a late-round cornerback, Marcus Cooper, and he ended up getting snatched by the Kansas City Chiefs.
10. Ryan Seymour. No. 62
He ostensibly is competing against veteran Adam Snyder for the jack-of-all trades role on the offensive line. Like Snyder, Seymour can play every spot, although he's been manning the backup right tackle position as of late. Look for him early if the 49ers are in a short-yardage situation and they go with extra blockers.
*11. Aaron Lynch. No. 59
This is your bonus player to watch. Lynch only played special teams against the Ravens but stood out by absolutely crushing a blocker on a Baltimore punt. Lynch is massive -- the biggest of the team's outside linebackers -- and powerful with very long arms. He likely will see action at left outside linebacker in the second half and promises to be a handful for any backup offensive tackle assigned to block him