Being No. 1 isn’t always good. Jimmy Garoppolo’s torn ACL in Week 3 of the NFL season tops the Top 10 list of 49ers stories in 2018.

Coming off a five-game win streak with their new quarterback under center to finish 2017, 49ers fans were hopeful for a playoff berth this season - until Garoppolo was carted off the field at Arrowhead Stadium in Kansas City, Mo., on Sept. 23.

Three months later, the 49ers will take a 4-11 record into their season finale against the Rams on Sunday in Los Angeles, but not all has been bad in the Bay Area. Nick Mullens has proved he’s an NFL quarterback, if not a threat to Garoppolo’s starting job, tight end George Kittle has produced a record-breaking season, and defensive tackle DeForest Buckner has piled on his sack total.

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Here are the top 10 49ers stories for 2018:

No. 1: Garoppolo’s knee injury

The 49ers came into the season as a dark-horse playoff contender with their new $137.5 million quarterback in tow. But San Francisco’s hype train came to a screeching halt in the fourth quarter at Kansas City in Week 3. Garoppolo, trying to will the 49ers back into the game after falling behind 35-7 in the first half, tore the ACL in his left knee on a play where it appeared he could have stepped out of bounds to avoid colliding with a defender. Garoppolo instead tried to push up the field on his left leg and ended his season.

San Francisco’s playoff hopes were kaput with Garoppolo out. Backup C.J. Beathard showed signs of improving after struggling as a rookie but gave the ball away at a terrible rate, and the 49ers went 0-5 in his starts before Nick Mullens was inserted into the lineup in Week 9 against the Raiders.

If anything, San Francisco learned a lot about Garoppolo’s value to the club by him being sidelined.

No. 2: Mullens’ ascension

The 49ers had strong quarterback play late in the season for the second year in a row. Instead of Garoppolo, a well-known player who joined the team in a splashy trade, Nick Mullens rose from obscurity to make the 49ers competitive in December. The undrafted free agent from Southern Mississippi was elevated from the practice squad because of Garoppolo’s injury, but he played well enough to keep Beathard on the bench after taking over when Beathard was injured.

Mullens made a huge splash in his debut against the hapless Raiders. He completed 16 of 22 passes for 262 yards and three touchdowns with no interceptions. His 151.9 passer rating was the second-highest for a quarterback making his starting debut since 1973. And his 1,995 yards passing in his first seven games is the third-most over that span since 1970.

It appears Mullens will be Garoppolo’s primary backup in 2019. The 49ers would be wise to hold on to Mullens and Beathard throughout the offseason while Garoppolo recovers.

No. 3: Young players regress

One of the most encouraging developments from the end of 2017 was the production of several young players, including members of Kyle Shanahan and John Lynch’s first draft class. Defensive lineman Solomon Thomas, linebacker Reuben Foster, cornerback Ahkello Witherspoon, receiver Trent Taylor and safety Adrian Colbert appeared to establish roles as valuable building blocks. Their improvement was among the reasons there was so much optimism surrounding the 49ers in the offseason.

But most of those players experienced regression in 2018 because of injury or otherwise. Thomas enters the season finale with one sack (he was nearest Raiders quarterback Derek Carr as he scrambled out of bounds for a loss). Witherspoon struggled for the most of the season opposite Richard Sherman. Taylor had offseason back surgery and didn’t show signs of recovering until late in the season. Colbert struggled before suffering a season-ending ankle injury in October. And Foster is no longer on the team.

No. 4: Foster released following domestic violence arrest

The 49ers hoped Foster’s tumultuous offseason would be a blip on the radar, but it was a sign toward a worrisome trend. Foster found himself in the crosshairs of the law, again, hours before the 49ers’ game at Tampa Bay on Nov. 25. He was arrested at the team hotel on domestic violence allegations following an incident with the same woman involved with his offseason arrest.

The 49ers cut Foster the morning after his arrest, citing a poor pattern of decision making. Foster was one of the 49ers’ most talented defenders, though his play took a step back in his second year. His release means the 49ers will have to make another sizable investment in a linebacker to play alongside promising rookie Fred Warner.

No. 5: Sherman’s arrival

One 49ers mandate in the offseason was to improve at cornerback while the team decided against bringing back starter Dontae Johnson, who struggled to finish 2017. So when Richard Sherman was released by the Seahawks last March, the 49ers swooped in quickly, agreeing to an incentive-laden three-year contract before the weekend was out.

Adding Sherman came with considerable risk. He would turn 30 soon after signing, which is long in the tooth for the position. And he was coming off a season-ending Achilles’ tear suffered the previous November. There was no guarantee Sherman would return to his All-Pro form, but he has been very good after struggling, at times, with his health early in the season. He heads into the season finale allowing one reception per 19.2 coverage snaps this season, according to Pro Football Focus, which is the best among cornerbacks.

No. 6: McKinnon’s absence

The 49ers raised eyebrows in the offseason by signing former Vikings backup Jerick McKinnon to a four-year, $30 million pact, making him one of the highest-paid running backs in the league. The former third-round draft pick had sky-high athletic potential but lacked the production with Minnesota to make the signing a slam dunk.

Then came training camp, when McKinnon appeared to be on his way to a sterling first season with the 49ers. He was a prominent target in the passing game - on screens and running routes from the slot - and was going to have a big role in Shanahan’s offense. But McKinnon tore his ACL during practice a week before the season opener. Some would argue McKinnon’s absence was a key reason the offense struggled early, because he was going to be relied on so heavily.

No. 7: Kittle’s rise to stardom

Perhaps the most encouraging development is the remarkable rise of tight end George Kittle, who broke the team’s season receiving record for the position in Week 14 with a historic performance. Kittle against the Broncos logged seven catches for 210 yards — all in the first half — also making him the only 1,000-yard tight end in club history.

Kittle is far and away the team’s leading pass catcher with 79 for 1,228 yards. To boot, he’s an excellent run blocker, which has paid dividends for a rushing attack that ranked in the top 10 throughout the season. Kittle’s rise is a boon for San Francisco after he fell to the fifth round of the 2017 draft largely because he never had more than 22 catches in a season at Iowa.

No. 8: A promising rookie class

Mentioning the 2018 rookie class should come with the caveat mentioned above: A promising first season doesn’t guarantee anything to the next. But it appears first-round pick Mike McGlinchey, second-rounder Dante Pettis and third-round choice Fred Warner have promising futures. Others, such as defensive backs D.J. Reed and Marcell Harris, look like they could be in the mix for starting jobs next year. The book is out on cornerback Tarvarius Moore, defensive linemen Kentavius Street and Jullian Taylor and receiver Richie James.

McGlinchey will have started every game at right tackle and enters Week 17 as Pro Football Focus’ top rookie offensive lineman, according to its grading system. Pettis was shut down with a team-high five touchdown catches after coming on in the past month, averaging 70 yards receiving in five games from Weeks 10-15, which paces out to 1,120 yards over a 16-game slate. Warner has played nearly every defensive snap at middle linebacker and will enter his second campaign with sky-high expectations.

No. 9: Buckner’s breakout

Defensive tackle DeForest Buckner had just three sacks last season but was still a darling among those who studied advanced metrics. He was at the top of the league in pressures and overall productivity despite his paltry sack total. But that changed in his third season. Buckner enters the finale with 12 sacks, three more than his first two years combined, including 7.5 over his last seven games.

Buckner was the 49ers’ biggest snub in Pro-Bowl recognition. He was named an alternate while Aaron Donald, Akiem Hicks and Fletcher Cox were given NFC nods. A strong case can be made for Buckner’s inclusion over Cox, a more noteworthy name who plays for last season’s Super Bowl champion. Buckner’s trajectory and production points to another increase in 2019.

No. 10: Shanahan, Lynch steering boat in right direction

The 49ers are 10-21 since hiring Shanahan and Lynch, but a strong argument can be made that the franchise is inching in the right direction. The team continues to play hard. Shanahan helped identify and develop Mullens into a capable player — one who might even garner trade interest in the offseason.

Young players are progressing. The locker room is cohesive. The organization seems on the same page, which hasn’t been the case in recent seasons. Suffice to say, the 49ers appear to be headed the right way, assuming they catch some breaks (like getting Garoppolo to play an entire season) and continue to add key pieces to the roster. Turnarounds happen quickly in the NFL. And though it might not be happening as fast as San Francisco would like, the future seems far less bleak entering this offseason than it did when the team had similarly bad records after 2015 and 2016.

This story was originally published December 27, 2018 6:42 PM.