The 49ers had a plan to absorb an injury to their starting quarterback. Neither they nor many other NFL teams have a fallback plan ready for dealing with injuries to two quarterbacks. After losing Trey Lance to a season-ending broken right ankle in Week 2, Kyle Shanahan's team has been dealt a second brutal blow. Jimmy Garoppolo is expected to miss the rest of the season after fracturing his left foot in Sunday's 33-17 win over the Dolphins.

The injury puts a damper on what is now a five-game winning streak for the 49ers and brings an end to what might have been the best stretch of Garoppolo's career. Over his past five starts, he completed nearly 72% of his passes, averaged 8.0 yards per attempt and threw eight touchdown passes without a pick, with the 70.8 QBR he posted good for eighth-best in football. As a free agent after the season, Sunday might have been Garoppolo's last game in a San Francisco uniform.

Let's look into the repercussions and impact of the Garoppolo injury, both on the 49ers and the rest of the league, through 2022 and into next season. San Francisco went all-in at the trade deadline last month, dealing significant draft capital for running back Christian McCaffrey, which makes their short-term future more complicated. 

Can the 49ers win games with Brock Purdy at quarterback?

As we saw Sunday, yes. After Garoppolo suffered his injury on the opening drive, Purdy came into the game. The rookie seventh-round pick, whose nine NFL passing attempts before Sunday came in a Oct. 23 loss to the Chiefs, played about as well as the 49ers could have hoped. He went 25-of-37 for 210 yards, throwing two touchdown passes against one pick. He took three sacks, but the 49ers scored 20 points on 10 drives with Purdy in the game before kneel-downs.

The offense was conservative, which was unsurprising given Purdy's inexperience and sudden move into the lineup. Purdy averaged just 5.3 air yards per pass attempt, the fewest of any other quarterback in the league. He threw just one attempt 20-plus yards downfield, an incompletion near the end zone to Deebo Samuel. His 40 dropbacks generated 0.1 passing EPA; he was essentially anonymous when it came to generating points for the offense. San Francisco won comfortably anyway.

The track record of seventh-round picks playing during their rookie season is pretty scary, frankly. Pro-ready passers don't fall to the seventh round, which means the quarterbacks who do come off the board during the final round of the draft are usually long-term projects with slim chances of succeeding.

Tom Brady famously turned into the greatest player in league history as a sixth-round pick, but the most notable seventh-round passers in recent memory might be Matt Cassel, who barely played during his time at USC, and Ryan Fitzpatrick, who played at a lower level at Harvard. Purdy put plenty on tape as a four-year starter at Iowa State.

Brady, Fitzpatrick and Kurt Warner obviously matured into much more than what their draft status would have projected at the professional level, but it took time. Brady was in his second season when he launched onto the national stage. Warner, an undrafted free agent, was a 28-year-old with years of experience in NFL Europe before his stunning breakout in his second season. Fitzpatrick didn't post an above-average passer rating as a starter until his 10th season.

Since the turn of the century, quarterbacks who were drafted in the seventh round have gone a combined 1-14 in their starts in their first active seasons. The one win came in 2004 from a 49ers quarterback in Ken Dorsey, who is better known now as the offensive coordinator and chief tablet destroyer for the Bills. Collectively, these passers have completed 53% of their passes, averaged 5.5 yards per attempt and thrown 15 touchdown passes against 32 picks. Even allowing for how passing levels have risen over that time, these quarterbacks have been sub-replacement options when forced into duty.

I'm not sure Purdy is better than any of the quarterbacks in that group, but I'm sure no rookie seventh-rounder in recent memory has been pressed into service in a better situation than the new starter in San Francisco. Most rookie seventh-rounders are toiling for terrible teams, some of whom were likely tanking, either knowingly or by accident.

Purdy enters into what might be the most welcoming situation for any quarterback. He's surrounded by superstar playmakers, with McCaffrey, Samuel, Brandon Aiyuk and George Kittle all active Sunday. His blind side will be locked down by Trent Williams, arguably the league's best left tackle. His coach is Shanahan, who many consider to be the most influential offensive coach of this generation.