Positivity has been surging for the San Francisco 49ers lately.

That is largely due to the contract extensions finalized with George Kittle, Brock Purdy, and Fred Warner. It means there will not be contract drama heading into training camp this year.

While it is stupendous that the 49ers will finally get to focus on football in camp, the reality is that they are still a team with some questions.

One of the biggest questions that Pro Football Focus has about the 49ers is about the youth on their defense, and how they can improve it. It’s a question that everyone will or should have about the 49ers.

They injected a ton of rookies into their defense, both out of necessity and to bring in a few of the best players available in the draft. Here is Pro Football Focus’ breakdown.

“The 49ers endured an unexpectedly cruel 2024 season in many ways, finishing 6-11 due to a boatload of injuries. After extending Brock Purdy, George Kittle and Fred Warner, San Francisco will need to count on newcomers to restore a defense that ranked 19th in EPA per play.

“General manager John Lynch attacked a weak front four with his first two picks in Mykel Williams (78.4 PFF overall grade) and Alfred Collins (87.2 PFF overall grade), each of whom is in line to start right away. Third-round pick Nick Martin (67.1 PFF overall grade) may also be thrust into starting duty next to Warner following Dre Greenlaw’s departure. Even Upton Stout (84.4 PFF overall grade) and C.J. West (88.1 PFF run-defense grade) may contribute in 2025, following in the footsteps of Renardo Green and Malik Mustapha last season.”

There is no bigger question surrounding the 49ers in 2025 than their defense. Bringing in so many rookies means they have a ton of variables.

They placed all of their chips on these players being adequate to boost the defense. That same question can apply to the second-year players on the defense.

Renardo Green and Malik Mustapha are integral players who have essentially been chalked up as proven talents already. But the reality is, they are still variables as well.

Mustapha is recovering from an ACL injury, and who knows how Green will look as the primary starter? If the majority of these players don’t pan out, the 49ers will be in serious trouble on defense.