Can you believe it’s already Week 15? The San Francisco 49ers’ impressive 2019 season has flown by, the team now in the final stages of preparation for Sunday’s matchup against the Atlanta Falcons at Levi’s Stadium. It has the makings of a letdown for Kyle Shanahan and Co., but the 49ers can’t afford to lose as they vie for positioning in the conference and division.

We’ll get into that and more in our weekly mailbag column. You’re welcome to drop questions in here for next week’s mailbag or tweet me @Rob_Lowder.

I would be the first person to object to parting ways with Sherman, even if Witherspoon and Moseley play well in his absence. Sherman’s playing at a high level and is worth every bit of his roughly $10 million cap hit in 2019 and ‘20. His value extends beyond the field, as well. Sherman’s one of the team’s most veteran players and a vocal leader in the locker room. He’s quickly established himself as a key component of the winning culture the 49ers have established this season. With expected extensions for tight end George Kittle and defensive lineman DeForest Buckner, the 49ers may quickly find themselves backed up against the salary cap. Even if money becomes tight, the 49ers should see Sherman as an invaluable asset with worth that greatly outweighs his price tag.

With the defense ailing, are you concerned with their ability to perform over the last three games? Don

It’s fair to expect some regression from the 49ers defense over the final stretch. The Falcons, Los Angeles Rams and Seattle Seahawks all own Top 10 offenses in the NFL. In addition to the talent of the opposition, the 49ers defense has also been hit with an onslaught of injuries. Sherman, cornerback K’Waun Williams, defensive end Dee Ford and safety Jaquiski Tartt have all been ruled out for Sunday’s matchup against Atlanta. All starters. The 49ers will need strong performances from their depth if they’re to keep pace over the next three games and capture the NFC West and No. 1 seed.

Is there more pressure on QB Jimmy Garoppolo considering the injuries on defense? Tony

Garoppolo was electric against the Saints, throwing for 349 yards and four touchdowns. It’s fair to say that the 49ers are going to need more of the same from their quarterback as the other side of the ball limps toward the end of the regular season. What was once a reliance on a dominant defense has slowly transitioned to wining through overwhelming firepower. This could very well be the method required over the next three games. Does Garoppolo feel pressured? Doubtful. But the 49ers’ ability to win will depend upon his continued dominance while taking care of the football.

What have been your favorite moments this season? Eli

Great question, Eli. Of course, I am inevitably going to leave out plenty that I won’t remember until this is published.

What are the chances coordinator Robert Saleh leaves to become a head coach? Josh

The 49ers’ defensive coordinator has seen his stock soar in 2019. Last season, Saleh’s defense set an NFL record for the fewest takeaways of any defense in the league’s history. With a handful of additions highlighted by a pair of edge rushers in Ford and Bosa, and another year in the scheme, the defense has taken on a new, dominant image. Even with Saleh’s success, I don’t expect he’ll land an NFL head coaching job yet. I certainly could be wrong. If the 49ers defense can replicate some of this success next season, I’d expect Saleh becomes a more coveted candidate.

What does the future hold for WR Trent Taylor? Chris

Taylor’s injury luck has been abysmal. After four healthy and highly productive seasons at Louisiana Tech, Taylor has seen two seasons with the 49ers supplanted by injury. A promising rookie year 2017 in which Taylor developed immediate chemistry with Garoppolo was followed by a disappointing 2018 marred by offseason back surgery. During training camp, Taylor was electric and easily the 49ers’ most productive wideout. A broken foot ended his hopes of a successful return to start the season followed by Multiple setbacks and infections ending his entire season outright. Taylor still has another year on his rookie contract and I’m sure the 49ers are eager to see if he can finally put the injuries behind him. If he can, Taylor’s ceiling is sky-high.

Who’s an under-the-radar player that could emerge for the 49ers in the postseason? Simon

I’m not sure he’s underrated anymore, but I’m going to go with receiver Kendrick Bourne. He’s had his ups-and-downs throughout the season, but has built up some momentum over the last couple games. Bourne’s ability to quickly separate has earned Garoppolo’s trust in the red zone, as well, with five touchdowns to his name throughout the season. Emmanuel Sanders is the clear leading receiver with Deebo Samuel developing a reputation, as well. With Kittle also in the mix, I could see Bourne taking advantage of being under the radar in the eyes of opposing defensive coordinators.

Do you think John Lynch and Kyle Shanahan expected the team to develop this quickly? Mac

I do. Kyle Shanahan and John Lynch both operate with a level of confidence that’s required for their positions. I think both have conviction in the decisions they’ve made, the personnel they acquired and the culture they established. Even in the midst of their last two losing seasons, I could tell the 49ers confidence within the locker room and throughout the staff was only growing, despite the results that hadn’t yet begun to manifest. Lynch and Shanahan deserve credit for the quick turnaround after inheriting a down-trodden roster, and if they told me they expected to be 11-2 before the season, I’d believe them.

The 49ers are expected to extend both DL DeForest Buckner and TE George Kittle. Do you think they keep DL Arik Armstead too? Cy

I think the 49ers will do everything in their power to retain Armstead after his breakout season. He’s an important element to the surging 49ers defense and their dominant defensive front. Armstead’s contributions can’t be ignored, totaling 46 tackles, 11 tackles for loss, 13 quarterback hits and 10 sacks this season - getting after the quarterback more than any other 49ers defender this season. A long-term extension or the franchise tag ($16-18 million) are the two options available to Lynch and salary cap guru Paraag Marathe. It won’t come easy, though, with the Buckner and Kittle’s extensions limiting the 49ers’ options.

How does the running back position shake out next season? Adrian

Raheem Mostert signed a three-year, $8.6 million contract extension with the 49ers in the offseason. He’ll remain with the team through 2021 and likely beyond. Raheem’s proven himself a starting-caliber running back along with his standout special teams ability. Matt Breida becomes a restricted free agent this offseason and the 49ers are likely to retain him with a first- or second-round tender. Tevin Coleman also has another season left on his two-year, $8.5 million contract. The obvious question mark is Jerick McKinnon, who missed his second consecutive season after struggling to rehab from a torn ACL before the start of 2018. McKinnon has a $9.2 million cap hit in 2020. He won’t be retained at that amount. The 49ers will likely ask McKinnon to restructure his deal if he’s to remain on the roster, and even that isn’t guaranteed.